Evaluación antifúngica del ozono contra Candida albicans: estudio in vitro / Antifungal evaluation of ozone against Candida albicans: in vitro study

Introducción: la Candida albicans (C. albicans) es un patógeno fúngico que puede causar infecciones superficiales o potencialmente mortales. Los biofilms de C. albicans muestran rasgos fenotípicos únicos, el más destacado es su notable resistencia a una amplia variedad de agentes antimicóticos. Una de las alternativas para inhibir el crecimiento de este microorganismo es el ozono debido a sus propiedades bactericidas, fungicidas y virucidas; sin embargo, escasa información ha sido reportada en C. albicans. Objetivo: el objetivo de este estudio fue evaluar el efecto fungicida del ozono en C. albicans. Material y métodos: la metodología consistió en agregar ozono a tubos de ensayo con medios de caldo nutritivo en diversas concentraciones y tiempos de ozonización. El efecto fungicida fue determinado con la determinación del número de colonias de C. albicans en agar nutritivo a través de procedimiento microbiológicos estandarizados por triplicado. Resultados: todas las muestras con ozono mostraron adecuados niveles de inhibición de crecimiento del microorganismo. Además, el efecto fungicida del ozono se encontró para ser significativamente dependiente del tiempo de ozonización y de la concentración. Conclusión: el uso de terapia con ozono podría tener potencial en el control de infecciones micóticas causadas por la presencia de C. albicans (AU)

Introduction: Candida albicans (C. albicans) is a fungal pathogen that can cause superficial or life-threatening infections. Biofilms of C. albicans display unique phenotypic traits, the most prominent being their remarkable resistance to a wide variety of antifungal agents. One of the alternatives to inhibit the growth of this microorganism is ozone due to its bactericidal, fungicidal and virucidal properties; however, little information has been reported on C. albicans. Objective: the objective of this study was to evaluate the fungicidal effect of ozone on C. albicans. Material and methods: the methodology consisted in adding ozone to test tubes with nutrient broth media in various concentrations and ozonation times. The fungicidal effect was determined by determining the number of colonies of C. albicans in nutrient agar through standardized microbiological procedures in triplicate. Results: all the ozone samples showed adequate levels of growth inhibition of the microorganism. Furthermore, the fungicidal effect of ozone was found to be significantly dependent on ozonation time and concentration. Conclusion: the use of ozone therapy could have potential in the control of fungal infections caused by the presence of C. albicans (AU)

Análisis microbiológico a corto y largo plazo del material usado para esterilizar instrumental odontológico / Short and long-term microbiological analysis of the material for sterilize dental instruments

Introducción: el material para empaquetar el instrumental odontológico, como pueden ser bolsas de tela, papel o plástico, es usado por profesionales de la salud; sin embargo, es necesario esclarecer la efectividad de cada uno y determinar el tiempo que permanece estéril luego del procedimiento. Objetivo: identificar la eficacia de tela, plástico y papel como materiales para esterilizar instrumental a corto y largo plazo. Material y métodos: se realizaron cultivos sólidos y líquidos de instrumental esterilizado en tres materiales y con diferentes tiempos de postesterilización. Se incubaron a 36 oC por 72 horas en condiciones aerobias y anaerobias. Los resultados se analizaron usando una prueba de Kruskal-Wallis, seguida de una prueba de Dunn. Resultados: los resultados mostraron que inmediatamente después del proceso de esterilización, los tres materiales son efectivos (Kruskal-Wallis test, p = 0.2752), 24 horas (p = 0.2492), siete (p = 0.0509) y 14 días (p = 0.0006). Veinticuatro horas posterior a la esterilización la tela no es efectiva, el plástico disminuye su efectividad y el papel sigue siendo efectivo. Conclusión: en nuestros resultados, el papel es la mejor opción para esterilizar instrumental (AU)

Introduction: material such as cloth, paper or plastic bags to wrap dental instruments is used by health professionals, however, it is necessary to clarify the effectiveness of each one and determine if it remains sterile after the procedure. Objective: to determine the effectiveness of cloth, plastic and paper as materials to sterilize dental instruments in the short and long term. Material and methods: we carry out solid and liquid cultures of sterilized instruments in three materials, at different post-sterilization times, incubated at 36 oC for 72 hours under aerobic and anaerobic conditions, and the results were analyzed using a Kruskal-Wallis test, followed by from a Dunn's test. Results: our results showed that immediately after the sterilization process the three materials are effective (Kruskal-Wallis; p = 0.2752), 24 hours (p = 0.2492), 7 (p = 0.0509) and 14 (p = 0.0006) days. Twenty-four hours after the cloth is not effective, plastic decreases its effectiveness and paper remain effective. Conclusion: in our results, paper is the best option to sterilize dental instruments (AU)

Hongos anamorfos biodegradan los libros del Área Histórica de la Universidad Central del Ecuador (UCE) / Anamorphous fungi biodegrade the books of the Historical Area from the Central University of Ecuador (CUE)

Determinamos los géneros de hongos anamorfos que contaminan los libros del área de cuarentena y limpieza, dentro del Área Histórica de la Universidad Central del Ecuador (UCE). Realizamos un hisopado aleatorio a una muestra representativa de 50 de estos libros de acuerdo a una Tabla militarizada estándar. También hisopamos como muestra preferencial a 21 libros gravemente contaminados con hongos. Los hisopados tuvieron una superficie de 5x5 cm, friccionando en la pasta, el borde y el interior de estos libros. Las 213 muestras tomadas fueron inoculadas en medio de cultivo Agar Malta. Los medios fueron incubados a una temperatura de 28°C durante 7 días. Realizamos observaciones por microscopía a 40 y 100x además de usar literatura especializada para la identificación hasta el nivel de género de hongos anamorfos. Los géneros más abundantes en este estudio fueron Penicillium (80,2%) y Mucor (8,1%). (AU)

We determined the genera of anamorphic fungi that contaminate the books in the quarantine and cleaning area, within the Historical Area of the Central University of Ecuador (CUE). We performed a random swab on a representative sample of 50 of these books according to a standard militarized Table. We also swabbed as a preferential sample 21 books seriously contaminated with fungi. The swabs had a surface area of 5x5 cm, rubbing on the paste, the edge and the interior of these books. The 213 samples taken were inoculated in Agar Malta culture medium. The media were incubated at a temperature of 28° C for 7 days. We made observations by microscopy at 40 and 100x in addition to using specialized literature for the identification down to the genus level of anamorphic fungi. The most abundant genus in this study were Penicillium(80,2%) and Mucor(8,1%). (AU)

Recuento de Streptococcus mutans sobre restauraciones realizadas con adhesivo con y sin carga de nanopartículas de óxido de zinc y cobre / Streptococcus mutans count on restorations made with adhesive with and without loading zinc and copper oxide nanoparticles

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

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

Eficacia del instrumento XP-endo Finisher y del sistema EndoActivator en la reducción/eliminación del biofilm bacteriano: un ensayo ex vivo / Ability of the XP-endo Finisher instrument and the EndoActivator system to reduce/eliminate of the bacterial biofilm: an ex vivo assay

Objetivos: Comparar ex vivo la eficacia del instrumento XP-endo Finisher y del sistema EndoActivator en la reducción/eliminación del biofilm microbiano en conductos radiculares infectados. Materiales y métodos: Se utilizaron 23 premolares inferiores humanos extraídos cuya longitud fue estandarizada en 17 mm. Todos los conductos se prepararon con el sistema WaveOne Gold Medium (#35.06). Los dientes se esterilizaron, se inocularon con Enterococcus faecalis y se separaron en dos grupos experimentales de 10 piezas cada uno. De los 3 dientes remanentes, 1 fue utilizado como control positivo y 2, como controles negativos. En el grupo 1, las soluciones irrigantes se agitaron con XP-endo Finisher. En el grupo 2, se utilizó EndoActivator. Se tomaron muestras antes de la contaminación, luego de esta y después de la agitación de los irrigantes mediante conos de papel estériles. La carga microbiana fue sembrada en agar sangre y los conos se cultivaron en caldo tripteína de soja. La remoción de la carga microbiana se determinó por la presencia o ausencia de turbiedad del medio. Las unidades formadoras de colonias (UFC) remanentes se cuantificaron y los resultados se categorizaron como R1 (≤10 UFC) o R2 (>10 UFC). Los datos fueron analizados mediante la prueba de Fisher. Resultados: No hubo diferencias significativas entre XP-endo Finisher y EndoActivator (P>0,05). El número de usos no influyó sobre la capacidad operativa de ambos instrumentos (AU)

Aim: To compare ex vivo the effectiveness of the XP-endo Finisher and the EndoActivator in biofilm reduction/ removal from infected root canals. Materials and methods: Twenty three extracted human single-rooted lower premolars were selected and standardised to 17 mm in length. All the canals were prepared with WaveOne Gold Medium reciprocating files (#35.06). The teeth were autoclaved and inoculated with Enterococcus faecalis. The infected teeth were then assigned to 2 experimental groups of 10 teeth each according to the final irrigation/agitation protocol. Of the three remaining teeth, one was used as a positive control, and the other two were used as negative controls. In Group 1 the irrigating solutions were agitated with XP-endo Finisher while in Group 2 the EndoActivator was used. All root canals were sampled before and after contamination, and again after irrigant agitation with sterile paper points. The microbial load was spread on blood agar plates and the paper points were cultured in sterile trypticase soy broth. The removal of the microbial load was determined by visual observation of the turbidity of the media and by quantification of the number of colony-forming units (UFC). The results were categorized as R1 (≤10 UFC) or R2 (>10 UFC). Data were analysed by the Fisher's exact test at P<0.05. Results: No significant differences was found between XP-endo Finisher and EndoActivator (P>0.05) regarding their effectiveness in the reduction/removal of the microbial biofilm. The number of uses of both instruments did not affect their operative performance (AU) Conclusion: XPF and EA were both equally effective for microbial biofilm reduction/removal from ex vivo infected root canals (AU)

Subgingival microbiological profile of periodontitis patients in Dominican Republic

The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group AAcid Etching with 37% H3PO4 gel for 15 s; Group B5% NaOCl for 60 s + Acid Etching with 37% H3PO4for 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by KolgomorvSmirnov test and the nonparametric unpaired MannWhitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern (AU)

El objetivo del estudio fue evaluar la desproteinización del esmalte primario a través de los tipos de patrones de grabado, con y sin NaOCl 5% utilizado antes del grabado ácido con H3PO4 37%. Quince dientes primarios humanos extraídos se seleccionaron al azar para el presente estudio in vitro, se prepararon bloques de 1mm x 1 mm y se dividieron en dos grupos (n = 21). Estos grupos se trataron de la siguiente manera: Grupo A: Grabado ácido con H3PO4 37% en gel durante 15 segundos; Grupo B: NaOCl 5% durante 60 segundos + Grabado ácido con H3PO4 37% durante 15 segundos. Las muestras se prepararon para el análisis de microscopía electrónica de barrido. Las imágenes obtenidas se evaluaron principalmente por la calidad de los grabados tipo I y II de la superficie del esmalte primario, utilizando el software Image J. Los datos se analizaron en cuanto a su normalidad mediante la prueba de KolgomorvSmirnov, se utilizó pruebas no paramétricas: Prueba de MannWhitney no pareada. Como resultado, se encontró que el área de superficie media de los valores de patrón de grabado de tipo I y II para el Grupo A era 1922,314 µm2 y el Grupo B era 3840,473 µm2. Finalmente, llegamos a la conclusión de que se puede usar la desproteinización con NaOCl 5% antes del grabado ácido para aumentar el área de adhesión y la calidad del patrón de grabado (AU)

Comparación bacteriana de 30 piezas de alta velocidad antes y después de ser utilizadas en la facultad de odontología, Región Veracruz / Bacterial comparison of 30 high speed handpieces before and after being used at the school of dentistry, Veracruz Region

Introducción: en los procedimientos odontológicos se está expuestoa gran cantidad de microorganismos y las intervenciones clínicas provocan un contacto directo o indirecto con éstos, ya sea a través del instrumental, equipo odontológico contaminado con saliva, sangre, exudados, etcétera. Por esta razón debe tomarse en cuenta el tipo de contaminación de las piezas de mano por ser parte del equipo de uso cotidiano para realizar tratamientos odontológicos. Objetivos generales:Determinar la carga bacteriana en las piezas de alta velocidad antes y después de su uso en diferentes clínicas de la Facultad de Odontologíade la UV Región Veracruz. Metodología: Investigación transversal, descriptiva y observacional. Material y métodos: Se seleccionaron al azar 30 piezas de mano de los estudiantes de la Universidad Veracruzana Facultad de Odontología Región Veracruz, a las cuales se tomó una muestra con un hisopo de algodón antes y después de su uso en la práctica dental. Se realizaron cultivos con las muestras obtenidas que se observaron durante tres días seguidos bajo microscopio para comprobar la presencia de colonias bacterianas. Resultados: De las30 piezas antes de ser utilizadas se detectó Bacillus grampositivos en24 por ciento de las muestras; en 20 por ciento Bacillus gramnegativos, en 6 por ciento Streptobacillus gram-positivos; en 20 por ciento Staphylococcus grampositivos; en 3 por ciento Cocobacillus gramnegativos y en 22 por ciento Actinomyces gramnegativos. El restante 2 por ciento no reveló unidades formadoras de colonias (UFC). En un segundo muestreo, 33 por ciento desarrolló Bacillus grampositivos, 10 por cientoBacillus gramnegativos, 20 por ciento adquirió Sthapylococcus grampositivos, 3 por ciento Sthapylococcus gramnegativo y 34 por ciento no reveló UFC. Conclusión:En el primer muestreo se detectaron microorganismos en 98% de laspiezas de mano, mientras que en el segundo muestreo 66% se contaminócon microorganismos y en 34% no se observó contaminación.

Introduction: dental activity is exposed to a lot of microorganisms,and clinical interventions have a direct or indirect contact with them.Whether through the instruments, dental equipment contaminatedwith saliva, blood, etc; so you should take into account the type ofcontamination of handpieces for being the most widely used equipmentfor dental treatment. General Objectives: Determine the bacterialload in high-speed parts before and after being used in diff erentclinical uses in Dentistry School at UV, Veracruz. Methodology:Cross-sectional, descriptive and observational research. Materialand methods: 30 pieces of students from the Universidad VeracruzanaSchool of Dentistry, Veracruz region, which a sample was takenwith a swab to pieces before and after use in dental practice wererandomly selected. Cultures with samples obtained observedduring three days in a row microscope to determine the presenceof bacterial colonies were made. Results: Of the 30 pieces beforebeing used 24% of Bacillus Gram-positive samples were found; 20%Bacillus Gram-negative, Gram-positive Streptobacillus 6%; 20%Gram-positive Staphylococcus, 3% developed Coccobacillus Gramnegativeand 22% Gram negative Actinomyces. The remaining 2%no colony forming units development (UFC). In a second sampling;33% developed Bacillus Gram-positive, Gram-negative Bacillus10%, 20% obtained Sthapylococcus Gram-positive, Gram-negativeSthapylococcus 3% and 34% did not develop colony forming unit(CFU). Conclusion: In the first sampling 98% of the pieces were microorganism growth, while in the second 66% and the presence ofmicroorganisms obtained 34% no development.

Biosynthesized silver nanoparticles: are they effective antimicrobials?

BACKGROUND Silver nanoparticles (AgNPs) are increasingly being used in medical applications. Therefore, cost effective and green methods for generating AgNPs are required. OBJECTIVES This study aimed towards the biosynthesis, characterisation, and determination of antimicrobial activity of AgNPs produced using Pseudomonas aeruginosa ATCC 27853. METHODS Culture conditions (AgNO3 concentration, pH, and incubation temperature and time) were optimized to achieve maximum AgNP production. The characterisation of AgNPs and their stability were evaluated by UV-visible spectrophotometry and scanning electron microscopy. FINDINGS The characteristic UV-visible absorbance peak was observed in the 420-430 nm range. Most of the particles were spherical in shape within a size range of 33-300 nm. The biosynthesized AgNPs exhibited higher stability than that exhibited by chemically synthesized AgNPs in the presence of electrolytes. The biosynthesized AgNPs exhibited antimicrobial activity against Escherichia coli, P. aeruginosa, Salmonella typhimurium, Staphylococcus aureus, methicillin-resistant S. aureus, Acinetobacter baumannii, and Candida albicans. MAIN CONCLUSION As compared to the tested Gram-negative bacteria, Gram-positive bacteria required higher contact time to achieve 100% reduction of colony forming units when treated with biosynthesized AgNPs produced using P. aeruginosa.

Directriz para reducir el riesgo de transmisión de mycobacterium abscessus durante la práctica clínica odontológica / Guideline to reduce the risk of transmission of mycobacterium abscessusin clinical dental practice

Las medidas de bioseguridad están predestinadas a reducir el riesgo de transmisión de microorganismos a partir de fuentes de infección reconocidas o no reconocidas en clínicas dentales vinculadas con lacontaminación de los materiales, aparatos y/o instrumentos. Un microorganismo reemergente es el Mycobacterium abscessus, que es unabacteria ambiental que puede ocasionar problemas de salud muy serios, por lo que debe ser controlada y prevenida su transmisión.

Biosafety measures are designed to reduce the risk of transmission ofmicroorganisms from recognized or unrecognized sources of infectionin dental procedures associated with the contamination of materials,apparatus, and/or instruments. One reemerging microorganism isMycobacterium abscessus, which is an environmental bacterium thatcan cause serious health problems and therefore needs to be controlledand prevented.

Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

Abstract Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

Estudio de dos técnicas de desinfección en un material de impresión / Study of the effect of two disinfection techniques on an impression material

El controlar la infección es una obligación profesional de fundamental importancia así como la reducción del riesgo de contaminacióncruzada durante los procedimientos clínicos para la calidad y la seguridad en la práctica dental. Material y métodos: Un total de 27 impresiones individuales fueron obtenidas de pacientes, las cuales se dividieron en tres grupos para su tratamiento. Grupo control: nueve impresiones individuales usando una silicona por adición, sin desinfectar,fueron sumergidas en agua bidestilada durante 10 minutos. Grupo A: nueve impresiones individuales fueron sumergidas en glutaraldehído al 2 por ciento durante 10 minutos. Grupo B: nueve impresiones individuales fueron esterilizadas mediante autoclave a 134 oC por 15 minutos a 15 psi. Resultados: Después de realizar el conteo bacteriano respectivo de cada grupo de estudio, se observó el crecimiento bacteriano en dosgrupos, siendo notoria la falta de crecimiento en las muestras del grupoB, mientras que en el grupo control la cuenta fue mayor que en el grupo A. Conclusiones: El lavado de la impresión reduce la cantidad de microorganismos presentes mas no la desinfecta. El glutaraldehído al 2 por ciento fue eficaz en la eliminación de microorganismos no esporulados provenientes de la cavidad oral presentes en las impresiones conmaterial elastomérico. La eliminación completa de microorganismos puede ser lograda mediante la esterilización de las impresiones con material elastomérico...

Estudio de la actividad antimicrobiana de una crema dental en gel con EDS frente a Streptococcus mutans y Actinobacillus actinomycetemcomitans / A study of the antimicrobial activity of a EDS-containing dental gel against Streptococcus mutans and Actinobacillus actinomycetemcomitans

Determinar la actividad antimicrobiana de la pasta en gel de dientes contra dos microorganismos: mutans Streptococccus y Actinobacillus actinomycetemcomitans...

Fungal contamination and disinfection of dental chairs, Teresina, Piauí, Brazil / Contaminação de fungos e desinfecção em cadeiras odontologicas, Teresina, Piauí, Brasil

The aim of this study was to analyze fungal contamination on dental chairs at the clinic of a Higher Education Institution in TeresinaPI, Brazil, and to evaluate the effectiveness of different disinfectants: 70% alcohol and 1% sodium hypochlorite. We selected the five sites with most contact between patient and chair: headrest, backrest, armrests, seat and foot rest. Samples were collected from these sites on 14 chairs and inoculated in agar Sabouraud culture medium containing chloramphenicol. Pathogenic fungi were isolated from all sampling sites on the chairs. Highest frequencies were found on footrest, followed in decreasing order by seat, backrest, armrests and headrest. Fourteen species of filamentous fungi were identified, belonging to the genera Alternaria, Aspergillus, Cladosporium, Curvularia, Drechslera, Fusarium, Penicillium and Paecillomyces. After sampling, seven chairs were disinfected with 70% alcohol and seven with 1% sodium hypochlorite, and samples were taken again using the same procedure. No fungal growth was detected following disinfection with sodium hypochlorite, which was clearly more effective than alcohol, after which there was still fungal growth. This study highlights the need for the biosafety protocol to include cleaning and disinfection of dental chairs with 1% sodium hypochlorite after each attendance in order to prevent crossinfection.

O objetivo deste estudo foi analisar contaminação fúngica em cadeiras odontológicas na clínica de uma Instituição de Educação Superior em TeresinaPI, Brasil, e avaliar a efetividade de diferentes desinfetantes: álcool 70% e hipoclorito de sódio 1%. Nós selecionamos os cinco locais com maior contato entre o paciente e a cadeira: encosto da cabeça, das costas, dos braços, assento e encosto dos pés. As amostras foram coletadas destes locais das 14 cadeiras e inoculadas em meio de cultura agarSabouraud contendo cloranfenicol. Fungos patogênicos foram isolados de todos os locais de amostragem das cadeiras. As frequências mais altas foram encontradas no encosto dos pés, seguido em ordem decrescente pelo assento, encosto das costas, dos braços e encosto da cabeça. Quatorze espécies de fungos filamentoso foram identificados, pertencente aos gêneros Alternaria, Aspergillus, Cladosporium, Curvularia, Drechslera, Fusarium, Penicillium e Paecillomyces. Após a coleta, sete cadeiras foram desinfe tadas com álcool 70% e sete com hipoclorito de sódio 1%, e as amostras foram colhidas novamente usando o mesmo procedimento. Não foi detectado crescimento fúngico após desinfecção com hipoclorito de sódio, que foi claramente mais efetivo que o álcool, do qual ainda houve crescimento fúngico.Este estudo destaca a necessidade da inclusão no protocolo de biossegurança a limpeza e desinfecção das cadeiras odontológicas com o hipoclorito 1% após cada atendimento, a fim de prevenir infecções cruzadas.

Microbiological contamination in digital radiography: evaluation at the radiology clinic of an educational institution / Contaminação microbiológica em radiografias digitais: avaliação da clínica de radiologia de uma instituição de ensino

The aim of this study was to evaluate the contamination rate of intraand extraoral digital Xray equipment in a dental radiology clinic at a public educational institution. Samples were collected on three different days, at two times in the day: in the morning, before attending patients, and at the end of the day, after appointment hours and before cleaning and disinfection procedures. Samples were collected from the periapical Xray machine (tube head, positioning device, control panel and activator button), the panoramic Xray machine (temporal support, bite block, control panel and activator button), the intraoral digital system (sensor), and the digital system computers (keyboard and mouse). The samples were seeded in different culture media, incubated, and colonyforming units (CFU/mL) counted. Biochemical tests were performed for suspected colonies of Staphylococcus, Streptococcus and Gramnegative bacilli (GNB). Fungi were visually differentiated into filamentous fungi and yeasts. The results indicated the growth of fungi and Staphylococcus from all sampling locations. GNB growth was observed from all sites sampled from the intraoral Xray equipment. On the panoramic unit, GNB growth was observed in samples from activator button, keyboard and mouse. In general, a higher number of CFU/mL was present before use. It can be concluded that more stringent protocols are needed to control infection and prevent Xray exams from acting as vehicle for cross contamination.

O objetivo neste estudo foi avaliar o índice de contaminação dos equipamentos de radiografias digitais intra e extrabucais da clínica de radiologia odontológica de uma instituição pública de ensino. As amostras foram coletadas em três dias distintos, em dois momentos: pela manhã, antes dos atendimentos clínicos, e ao final do dia, após os atendimentos e antes dos procedimen tos de limpeza e desinfecção. As amostras foram coletadas do aparelho de raios X periapical (cabeçote, braço articular, painel de controle e botão disparador); do aparelho de raios X panorâmico (apoio temporal, bloco de mordida, painel de controle e botão disparador); do sistema digital intrabucal (sensor); dos computadores dos sistemas digitais (teclado emouse). As amostras foram semeadas em diferentes meios de cultura e, após incubação, foram contadas as unidades formadoras de colônia (UFC/mL). Testes bioquímicos foram realizados para colônias suspeitas de Staphylococcus, Streptococcus e bastonetes Gram negativos(BGN). Os fungos foram diferenciados visualmente em fungos filamentosos e leveduras. Os resultados indicaram crescimento de fungos e Staphylococcus em todos os locais amostrados. Em relação aos BGN, houve crescimento em todos os locais coletados do equipamento radiográfico intrabucal. No aparelho panorâmico, houve crescimento de BGN apenas no botão disparador, teclado e mouse. De maneira geral, houve maior número de UFC/mL antes do uso. Pode se concluir que é necessário implantar protocolos mais rigorosos de controle de infecção na prática radiológica, evitando que a obtenção de exames radiográficos seja um veículo para contaminação cruzada na FO/UFJF.

Mixed biofilms formed by C. albicans and non-albicans species: a study of microbial interactions

Abstract Most Candida infections are related to microbial biofilms often formed by the association of different species. The objective of this study was to evaluate the interactions between Candida albicans and non-albicans species in biofilms formed in vitro. The non-albicans species studied were:Candida tropicalis, Candida glabrata andCandida krusei. Single and mixed biofilms (formed by clinical isolates of C. albicans and non-albicans species) were developed from standardized suspensions of each strain (107 cells/mL), on flat-bottom 96-well microtiter plates for 48 hour. These biofilms were analyzed by counting colony-forming units (CFU/mL) in Candida HiChrome agar and by determining cell viability, using the XTT 2,3-bis (2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide colorimetric assay. The results for both the CFU/mL count and the XTT colorimetric assay showed that all the species studied were capable of forming high levels of in vitro biofilm. The number of CFU/mL and the metabolic activity of C. albicans were reduced in mixed biofilms with non-albicans species, as compared with a singleC. albicans biofilm. Among the species tested, C. krusei exerted the highest inhibitory action against C. albicans. In conclusion, C. albicans established antagonistic interactions with non-albicans Candida species in mixed biofilms.

Efecto antimicrobiano de una solución de superoxidación con pH neutro para desinfección de cavidades clase I / Effectiveness of a neutral pH super-oxidized solution for antimicrobial disinfection of class I cavities

Objetivo: determinar la disminución de la carga bacteriana en dentina de cavidades clase I posterior a la aplicación de clorhexidina 2 por ciento en comparación con la aplicación de solución de superoxidación con pH neutro. Material y métodos: Se realizó un estudio transversal clínico, a 30 pacientes en el Área de Clínicas de la Facultad de Estomatología en la Universidad Autónoma de San Luis Potosí, de los cuales se obtuvieron 60 muestras en cavidades clase I en primeros y segundos molares inferiores permanentes, previas al tratamiento y 60 posteriores que se dividieron en tres grupos, grupo control (n = 20), grupo A correspondiente a clorhexidina al 2 por ciento (n = 20) y grupo B correspondiente a solución de superoxidación con pH neutro (n = 20), posteriormente las muestras fueron llevadas al laboratorio donde se realizó una dilución seriada, para posteriormente sembrar las muestras en placas de agar soya tripticaseina y hacer el conteo de UFC después de haber sido incubadas 24 horas. Resultados: Se realizó una comparación de todos los grupos en cuanto a la disminución de carga bacteriana pretratamiento y postratamiento. Se observó diferencia es tadística significativa en el grupo tratado con clorhexidina al 2 por ciento (p < 0.01) mientras que en los grupos tratados con agua destilada y solución de superoxidación con pH neutro no fueron significativas, ambas con una (p > 0.05) entre las muestras pretratamiento y postratamiento. Conclusiones: Se logró obtener muestras en primeros y segundos molares inferiores en las que se cuantificaron microorganismos previos y posteriores al tratamiento mediante la cuantificación de UFC. Se encontraron diferencias significativas entre grupos, por lo que podemos decir de acuerdo con nuestros resultados que la clorhexidina al 2 por ciento tiene mayor efecto antimicrobiano en la desinfección de cavidades clase I que la solución de superoxidación con pH neutro.

background: Dental caries is a disease characterized by demineralization of the hard tissues of the tooth. If left untreated, it leads to cavitation, discomfort, pain, and the eventual loss of the tooth. A range of antiseptics have been used to eliminate microorganisms from cavities, one of the most common being chlorhexidine, due to the advantages it offers. Nowadays there are products available that offer not only the same microbicidal capacity, but also a greater half-life and superior tissue compatibility. One new option for cavity disinfection is pH neutral super-oxidation solution. Objective: To determine the decrease in bacterial load in the dentin of class I cavities following the application of 2% chlorhexidine compared to a neutral pH over-super-oxidized solution. Material and methods:A clinical cross-sectional study was conducted involving a total of 30 patients at the Faculty of Stomatology Clinics of the Autonomous University of San Luis Potosí, from whom 60 samples were obtained from class I cavities in first and second permanent lower molars prior to treatment and 60 following...

Antiseptic mouthwashes: in vitro antibacterial activity / Antissépticos bucais: atividade antibacteriana

Mouthwashes are used as an adjunct to tooth brushing for improving breath and preventing oral diseases. The aim of this study was to compare the in vitro Maximum Inhibitory Dilution (MID) of 3 mouthwashes with different active ingredients against mutans streptococci (MS). The products analyzed were Periogard, Cepacol and Plax Fresh Mint. Theirantibacterial activity was assessed in duplicate in 96-well microtiter plates against 36 clinical isolates of MS. Each mouthwash was submitted to a serial two-fold dilution (1/2.5 to 1/5120) using double concentration of Tryptose Soy Broth with 1.0% yeast extract. The final volume in each well was 100mL plus 5 mL of a bacterial suspension, equivalent to 107 CFU/mL. They were incubated microaerobically at 37ºC for48 hours and the MIDs determined. MID was 1/320 forPeriogard and Cepacol, and 1/20 for Plax. Statisticalanalysis revealed that the MID of Periogard MID did not differ from that of Cepacol (p>0.05), and was higher than that of Plax (p<0.05). In conclusion, the antiseptic mouthwashes containing chlorhexidine (Periogard) and cetylpyridinium chloride (Cepacol) had higher in vitroantibacterial activity(MID) against MS than the antiseptic mouthwash containing triclosan (Plax), according to microbiological method employed.

Os antissépticos bucais são utilizados mundialmente como adjuvantes da escovação para melhoria do hálito e prevenção de doenças bucais infeciosas. O objetivo deste estudo foi comparar in vitro a Diluição Inibitória Máxima (DIM) de 3 antissépticos bucais com diferentes princípios ativos contra estreptococos do grupo mutans (EGM). Os produtos analisados foram Periogard, Cepacol e Plax FreshMint. A atividade antibacteriana foi avaliada em duplicata em placasde microtilulação de 96 poços contra 36 isolados clínicos de EGM. Cada antisséptico bucal foi submetido a diluição dupla seriada (1/2,5 a 1/5120) com o emprego de concentração dupla de TryptoseSoyBrothwith adicionado de 1,0% de extrato de levedura. O volume final em cada poço foi de 100 mL mais 5mL da suspensão bacteriana equivalente a 10 UFC/mL. A incubação foi realizada em microaerofilia a 37ºC por 48 horas e a DIM deteminada. Periogard e Cepacol apresentaram DIM de 1/320, e Plax de 1/20. Os resultados submetidos asanálises estatísticas revelaram que a DIM do Periogard não foi diferente do Cepacol(p>0,05) sendo maior que do Plax (p<0,05). Em conclusão, os antissépticos bucais contendo clorexidina (Periogard) e cloreto de cetilpiridínio (Cepacol) demonstraram maior atividade antibacteriana in vitro (DIM)contra os EGM do que o antisséptico bucal contendo triclosan (Plax) de acordo com o método microbiológico utilizado.

Occurrence of Porphyromonas gingivalis and its antibacterial susceptibility to metronidazole and tetracycline in patients with chronic periodontitis

La periodontitis crónica es una enfermedad infecciosa multifactorialasociada a bacilos Gram-negativos anaeróbicos estrictos que se encuentran inmersos en la biopelícula subgingival. Porphyromonas gingivalis, importante patógeno periodontal, es frecuentemente detectado en pacientes con periodontitis crónica. Los aislamientos clínicos de P. gingivalis tienden a ser susceptibles a la mayoría de agentes antimicrobianos; sin embargo, se tiene poca información sobre la susceptibilidad antimicrobiana invitro. El objetivo de este estudio fue determinar la frecuencia de P. gingivalis en pacientes con periodontitis crónica y determinar la susceptibilidad antimicrobiana en términos de concentración inhibitoria mínima (CIM) de los aislamientos clínicos a metronidazol y tetraciclina. Se realizó un estudio observacional descriptivo enel que se incluyeron 87 pacientes con periodontitis crónica. Las muestras tomadas con conos de papel de la bolsa periodontal se depositaron en caldo tioglicolato, se incubaron durante 4 horas a 37 oC en anaerobiosis y se resembraron en agar anaeróbico Wilkins-Chalgren (Oxoid). La identitficación de los aislamientos serealizó con el sistema RapIDTM ANA II (Remel) y la susceptibilidadantibiótica para metronidazol y tetraciclina se evaluó mediante la técnica M.I.C.Evaluator (M.I.C.E., Oxoid). En 30 de los 87 pacientes con periodontitis crónica se identificó P. gingivalis, lo que representa una frecuencia de 34.5 por ciento. Todos los 30 aislamientos (100 por ciento) fueron sensibles al metronidazol con valores de CIM desde 0.015 hasta 4 ug/ml. En cuanto a tetraciclina, 27 aislamientos(90 por ciento) fueron sensibles con valores de CIM desde <0.015 hasta4 ug/ml; los restantes 3 aislamientos (10%) fueron resistentes a tetraciclina con valores de CIM de 8 ug/ml. En cuanto a edad, género, profundidad de bolsa, nivel de inserción clínico y severidad de la periodontitis no se presentaron diferencias estadísticamentesignificativas

Atividade antimicrobiana e sinérgica das frações das folhas de Schinopsis brasiliensis Engl. frente a clones multirresistentes de Staphylococcus aureus / Antimicrobial and synergic activity of fractions from the leaves of Schinopsis brasiliensis Engl. against Staphylococcus aureus multiresistant clones

No presente estudo objetivou-se avaliar a atividade antimicrobiana e sinérgica de 4 frações das folhas de Schinopsis brasiliensis Engl (F1', F2', F1" e F2") frente às cepas Staphylococcus aureus MRSA multirresistentes. Os métodos utilizados foram poços de difusão em ágar, concentração mínima inibitória (CMI) - diluição em ágar, e bioautografia. Nos resultados bioautográficos observou-se três halos de inibição relacionados, no mínimo, à quatro constituintes ativos; sendo dois deles isolados das folhas (galato de metila e ácido gálico). A F2" (200∝g/mL) apresentou halos de inibição de 16 e 19mm frente as cepas de S. aureus multirresistente e Klebsiella pneumoniae, e CMI 100∝g/mL, respectivamente. Quanto as análises das associações das frações F1" ou F2" (25 e 50∝g/mL) com a tetraciclina e oxacilina, mostraram ações aditiva e sinérgica para a F2" (50∝g/mL), embora não suficiente para que a CMI atingisse valores inferiores a 2 e 4∝g/mL, necessário para serem classificadas como cepas sensíveis a oxacilina e tetraciclina, respectivamente. "Assim, conclui-se que a F2" das folhas de S. brasiliensis apresentou potencial antimicrobiano frente às cepas de S. aureus MRSA multirresistentes e que as associações das frações com os antibióticos testados não apresentaram benefícios não justificando o uso concomitante.

The aim of this study was to evaluate the antimicrobial and synergic activity of 4 leaf fractions of Schinopsis brasiliensis Engl (F1', F2', F1" and F2") against multidrug-resistant Staphylococcus aureus strains. The used methods were agar well diffusion, minimum inhibitory concentration (MIC) - agar dilution, and bioautography. The bioautographic results showed three inhibition zones that corresponded to at least four active compounds, two of which (methyl gallate and gallic acid) have already been isolated from leaves. The F2" (200∝g/mL) fraction showed inhibition zones of 16 mm and 19 mm against S. aureus multidrug-resistant and Klebsiella pneumoniae strains and a MIC value of 100∝g/mL, respectively. The analyses of associations of fraction F1" or F2" (25 and 50∝g/mL) with tetracycline and oxacillin showed additive and synergistic action for F2" (50∝g/mL), although it was not enough to decrease the MIC values to less than 2 and 4∝g/mL, necessary to classify the strains as susceptible to oxacillin and tetracycline, respectively. Thus, it was concluded that F2" from the leaves of S. brasiliensis showed antimicrobial potential against multidrug-resistant MRSA strains, and the associations of the fractions with the tested antibiotics showed no benefits, not justifying their concomitant use.