Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: A novel device developed by J. Morita can generate electromagnetic stimulation (EMS) into the root canal. Objectives: The purpose of this study was to determine the anti-biofilm effect of EMS combined with low concentrations of NaOCl against an established biofilm of Enterococcus faecalis in an in vitro human tooth model. Materials and Methods: Single rooted human teeth were standardized and an E. faecalis biofilm was established in the canal. The specimens were subject to six treatment groups: 1) 1.5% NaOCl; 2) 1.5% NaOCl and EMS; 3) 0.25% NaOCl; 4) 0.25% NaOCl and EMS; 5) saline and 6) saline and EMS. Biofilm was collected, plated, and the number of colony forming units (CFU)/mL was used to determine antibacterial activity. Results: The effect of treatment group on bacterial counts were made using one-way ANOVA followed by pair-wise comparisons. Although there was no significant difference between individual groups tested, there was statistically significant difference between the average difference between ‘treatments with EMS’ and ‘treatments without EMS.’ Conclusion: EMS can improve the antibacterial efficacy of NaOCl against an established biofilm of E. faecalis in an in vitro human tooth model

El objetivo del estudio fue determinar el efecto in vitro de la medicación intraconducto hidróxido de calcio con omeprazol frente al crecimiento bacteriano del Enterococcus faecalis. El diseño de estudio fue experimental. Los medicamentos hidróxido de calcio y omeprazol fueron diluidos, obteniéndose las concentraciones requeridas. Posteriormente, se colocó 9 ml de cada uno en placas petri, agregando 1 ml del inóculo; procediéndose a la siembra. No se observó Unidades Formadoras de Colonias (UFC), por lo que se evidencia que el efecto in vitro del hidróxido de calcio, así como la asociación de hidróxido de calcio con omeprazol inhiben el crecimiento de Enterococcus faecalis. Se realizó una prueba binomial donde los eventos esperados fueron que haya o no crecimiento bacteriano. La significación estadística fue del 5%. El estudio concluyó que la asociación in vitro de hidróxido de calcio con omeprazol, inhibió el crecimiento bacteriano del Enterococcus faecalis, sin evidenciarse potencialización con el uso del inhibidor de la bomba de protones.

El objetivo del presente estudio fue comparar la efectividad antibacteriana de la pasta de hidróxido de calcio con clorhexidina al 2% y la pasta de hidróxido de calcio con yodopovidona al 1%, frente al Enterococcus faecalis. El diseño de contrastación fue experimental. Se distribuyeron 10 placas Petri que contenían agar Müller Hinton a 40° C, sobre las cuales fue inoculada la bacteria Enterococcus faecalis. Además, estas fueron divididas de manera aleatoria en 3 segmentos cada una de acuerdo al tipo de pasta medicamentosa que se aplicó: grupo P1 (hidróxido de calcio + clorhexidina al 2%), grupo P2 (hidróxido de calcio + yodopovidona al 1%) y el grupo P3 o control (hidróxido de calcio + agua destilada). Finalmente, se procedió a la lectura de halos de inhibición a las 24 horas, 48 horas, 7 días, 14 días. Los datos fueron procesados a través del análisis de Tukey para determinar la diferencia de medias entre los grupos experimentales y el análisis de ANOVA con un nivel de significancia del 95%, utilizando el programa SPSS 20. Se concluyó que la pasta de hidróxido de calcio con clorhexidina al 2% fue más efectiva que la pasta de hidróxido de calcio con yodopovidona al 1% frente al crecimiento in vitro del Enterococcus faecalis.

Este estudio in vitro evaluó la influencia de la dentina sobre el efecto antibacteriano contra Enterococcus Faecalis ATCC 29212 de 2 concentraciones de Hipoclorito de Sodio (NaOCl) 2.5% y 5%. Se empleó polvo de dentina a partir de dientes humanos (84 µg/ml) y la supervivencia de la bacteria se evaluó realizando recuento de unidades formadoras de colonias (UFC) a los 10, 30 y 60 segundos. Los datos se analizaron con la prueba estadística ANOVA factorial no encontrándose diferencias estadísticamente significativas entre los grupos con dentina y sin dentina concluyendo que la dentina en este estudio no influyó en el efecto antibacteriano del Hipoclorito de Sodio en ninguna concentración, ni en los tiempos.

La flora de los conductos con fracaso de tratamiento endodóntico está formada por un limitado número de especies microbianas predominantemente gram positivas. Los microorganismos predominantes en piezas dentarias con periodontitis apical son los Streptococo no mutans, Enterococcus, Lactobacillus y Candida, los cuales al parecer sobreviven al tratamiento quimio-mecánico del conducto radicular. Uno de estos microorganismos, el Enterococcus faecalis, ha sido identificado como causa frecuente de infección del sistema de conductos radiculares en dientes con fracaso en el tratamiento endodóntico. Es probablemente la especie que mejor puede adaptarse y tolerar las condiciones exigentes en el conducto radicular obturado. Su erradicación con preparación químicomecánica, desinfección por medio de soluciones irrigantes y medicación intraconducto es difícil. El objetivo de esta investigación es evaluar la acción antibacteriana de la pasta de Hidróxido de Calcio con Paramonoclorofenol alcanforado y la pasta de Hidróxido de calcio con Yodoformo y su acción antibacteriana sobre el Enterococcus faecalis. El método para la investigación fue la de test de difusión en Agar Bilis Esculina. La cepa utilizada fue el Enterococcus faecalis ATCC 29212. Se realizaron 6 pozos de 5mm de diámetro en 10 placas con Agar Bilis Esculina. En los pozos se colocaron las pastas hidróxido de calcio con paramonoclorofenol alcanforado, hidróxido de calcio con yodoformo, paramonoclorofenol control positivo, glicerina control negativo. Luego las placas fueron colocadas en incubación a 37 ºC por 24 horas. Se procedió a la lectura de los halos de inhibición bacteriana siendo estos directamente proporcional a la actividad antibacteriana de la pasta sobre el Enterococcus faecalis. Los resultados demostraron que ambas asociaciones tenían acción antibacteriana contra el Enterococcus faecalis, siendo el hidróxido de calcio asociado al paramonoclorofenol alcanforado quien mostró mayor acción bactericida. / Tesis

Horizontal gene transfer transforms commensal E. faecalis into multidrug resistance (MDR) opportunistic pathogens causing diseases such as infective endocarditis (IE), septicemia, and urinary tract infections (UTI) (4,1). E. faecalis are among the top three leading causes of hospital-acquired infections and pheromone responsive plasmids (pCF10) are the most extensively characterized conjugative plasmids in E. faecalis infection (2,4). E. faecalis is a potential future public health concern because of the co-occurrence factors of antibiotic resistance and virulence traits (6)Plasmid-free commensal E. faecalis form homogenous biofilms that have a uniform distribution of the bacterial cell and a fluid-like movement (22). The introduction of the pheromone responsive plasmid pCF10 leads to the formation of heterologous rigid structures within the biofilm (22). In the current work, the timeline of biofilm tower formation was characterized. Tower formation was not observed in the commensal strain. The pCF10-containing bacteria formed a rigid base layer on day 1 and small aggregates on day 1. pCF10-containing biofilm forms heterologous towers on days two and three. Interestingly, mixed biofilms with both plasmid-containing and plasmid-free bacteria developed tower-like structures as early as day 1 and had larger resulting structures by day three. In the mixed population, we hypothesize that the induction of aggregation substance and cell clumping during plasmid transfer may further contribute to structure formation (5,10). Plasmid-free mCherry-labeled bacteria could be observed in the viscous biofilms between heterologous rigid structures; however, the rigid structures were predominantly composed of plasmid-containing cells. Occasionally, mCherry cells were observed in the rigid structures, we hypothesize that these cells represent transconjugants, where pCF10 was transferred by conjugation to mCherry-plasmid-free OG1RF. The formation of rigid structures can protect bacteria from antibiotics by reducing the penetration of the antibiotic but binding and sequestration of the antibiotic in the outer layers. Antibiotic resistance increased in the pCF10-containing biofilms as rigid structures were formed. We hypothesize that underflow, like that found in the gastrointestinal tract, the heterologous rigid structures may form protected microenvironments for sensitive regions of the biofilms. In future studies, fluorescently labeled antibiotics will be used to access the formation of protected microenvironments in biofilms underflow. Previous studies in the laboratory demonstrated that the presence of pCF10 protects E. faecalis from hydrogen peroxide oxidative stress. E. faecalis produces hydrogen peroxide. Higher levels of hydrogen peroxide can be detected in rigid structures. The presence of pCF10 is known to increase the size of heart vegetations during endocarditis and hydrogen peroxide is a known activator of platelet activation (12,19). In these studies, the presence of pCF10 increased platelet activation in pCF10 containing biofilms. Software toolboxes are currently being developed to quantitate visual observations. The role of hydrogen peroxide is supported in our preliminary experiment revealing catalase treatment reduced platelet activation. Studies are ongoing to mutate the aroc and menB gene of E. faecalis, which contribute to hydrogen peroxide production (35). We will compare platelet activation in knockout (double or single) E. faecalis and the wild-type strain. For future studies, several of the preliminary data need to be repeated to further the study. We will repeat quantitative hydrogen peroxide production in the catalase experiments. We will also finish knocking out the aroc and men B gene of E. faecalis responsible for hydrogen peroxide and then compare platelet activation to the control strain. / Microbiology and Immunology

Les entérocoques font partie de la flore normale intestinale des animaux et des humains. Plusieurs études ont démontré que les entérocoques d’origine animale pouvaient représenter un réservoir de gènes de résistance aux antibiotiques pour la communauté humaine et animale. Les espèces Enterococcus faecalis et Enterococcus faecium sont importantes en santé publique; elles sont responsables d’environ 12% de toutes les infections nosocomiales aux États-Unis. Au Canada, les cas de colonisation et/ou d’infections à entérocoques résistants à la vancomycine ont plus que triplé de 2005 à 2009. Un total de 387 isolats E. faecalis et E. faecium aviaires, et 124 isolats E. faecalis porcins ont été identifiés et analysés pour leur susceptibilité aux antibiotiques. De hauts pourcentages de résistance envers les macrolides et les tétracyclines ont été observés tant chez les isolats aviaires que porcins. Deux profils phénotypiques prédominants ont été déterminés et analysés par PCR et séquençage pour la présence de gènes de résistance aux antibiotiques. Différentes combinaisons de gènes de résistance ont été identifiées dont erm(B) et tet(M) étant les plus prévalents. Des extractions plasmidiques et des analyses par hybridation ont permis de déterminer, pour la première fois, la colocalisation des gènes erm(B) et tet(M) sur un plasmide d’environ 9 kb chez des isolats E. faecalis porcins, et des gènes erm(B) et tet(O) sur un plasmide de faible poids moléculaire d’environ 11 kb chez des isolats E. faecalis aviaires. De plus, nous avons démontré, grâce à des essais conjugatifs, que ces plasmides pouvaient être transférés. Les résultats ont révélé que les entérocoques intestinaux aviaires et porcins, lesquels peuvent contaminer la viande à l’abattoir, pouvaient représenter un réservoir de gènes de résistance envers la quinupristine-dalfopristine, la bacitracine, la tétracycline et les macrolides. Afin d’évaluer l’utilisation d’un antisérum polyclonal SA dans l’interférence de la résistance à de fortes concentrations de bacitracine (gènes bcrRAB), lors d’un transfert conjugatif répondant aux phéromones, un isolat multirésistant E. faecalis aviaire a été sélectionné. Après induction avec des phéromones produites par la souche réceptrice E. faecalis JH2-2, l’agrégation de la souche donatrice E. faecalis 543 a été observée ainsi que des fréquences de transfert élevées en bouillon lors d’une courte période de conjugaison. Le transfert conjugatif des gènes asa1, traB et bcrRAB ainsi que leur colocalisation a été démontré chez le donneur et un transconjugant T543-1 sur un plasmide de 115 kb par électrophorèse à champs pulsé (PFGE) et hybridation. Une CMI de > 2 048 µg/ml envers la bacitracine a été obtenue tant chez le donneur que le transconjuguant tandis que la souche réceptrice JH2-2 démontrait une CMI de 32 µg/ml. Le séquençage des gènes asa1, codant pour la substance agrégative, et traB, une protéine régulant négativement la réponse aux phéromones, a révélé une association de cet élément génétique avec le plasmide pJM01. De plus, cette étude présente qu’un antisérum polyclonal SA peut interférer significativement dans le transfert horizontal d’un plasmide répondant aux phéromones codant pour de la résistance à de fortes doses de bacitracine d’une souche E. faecalis aviaire multirésistante. Des isolats cliniques E. faecium d’origine humaine et canine ont été analysés et comparés. Cette étude rapporte, pour la première fois, la caractérisation d’isolats cliniques E. faecium résistants à l’ampicilline (EFRA) d’origine canine associés à CC17 (ST17) au Canada. Ces isolats étaient résistants à la ciprofloxacine et à la lincomycine. Leur résistance envers la ciprofloxacine a été confirmée par la présence de substitutions dans la séquence en acides aminés des gènes de l’ADN gyrase (gyrA/gyrB) et de la topoisomérase IV (parC/parE). Des résistances élevées envers la gentamicine, la kanamycine et la streptomycine, et de la résistance envers les macrolides et les lincosamides a également été observées. La fréquence de résistance envers la tétracycline était élevée tandis que celle envers la vancomycine n’a pas été détectée. De plus, aucune résistance n’a été observée envers le linézolide et la quinupristine-dalfopristine. Les données ont démontré une absence complète des gènes esp (protéine de surface des entérocoques) et hyl (hyaluronidase) chez les isolats canins EFRA testés tandis qu’ils possédaient tous le gène acm (adhésine de liaison au collagène d’E. faecium). Aucune activité reliée à la formation de biofilm ou la présence d’éléments CRISPR (loci de courtes répétitions palindromiques à interespaces réguliers) n’a été identifiée chez les isolats canins EFRA. Les familles de plasmide rep6 and rep11 ont significativement été associées aux isolats d’origine canine. Les profils PFGE des isolats d’origine humaine et canine n'ont révélé aucune relation (≤ 80%). Ces résultats illustrent l'importance d'une utilisation judicieuse des antibiotiques en médecine vétérinaire afin d’éviter la dissémination zoonotique des isolats EFRA canins. Nous pensons que ces résultats contribueront à une meilleure compréhension des mécanismes de résistance aux antibiotiques et de leurs éléments mobiles ainsi qu’à de nouvelles stratégies afin de réduire le transfert horizontal de la résistance aux antibiotiques et des facteurs de virulence. / Enterococci are part of normal intestinal gut flora of animals and humans. Many studies have shown that enterococci from animal origin could represent an antimicrobial resistance genes reservoir for the human community. The two species Enterococcus faecalis and Enterococcus faecium are important in public health; they are responsible for approximately 12% of all nosocomial infections in the United States. In Canada, cases of colonization and/or infections to vancomycin resistant enterococci have more than tripled from 2005 to 2009. A total of 387 poultry E. faecalis and E. faecium isolates, and 124 porcine E. faecalis isolates were identified and analyzed for their antibiotic susceptibilities. High percentages of resistance to macrolides and tetracyclines were found in both avian and porcine isolates. Two predominant phenotypic profiles were determined and analyzed by PCR and sequencing for the presence of antimicrobial resistance genes. Various combinations of antibiotic resistance genes were detected; erm(B) and tet(M) were the most common genes. For the first time, plasmid extraction and hybridization revealed colocalization of erm(B) and tet(M) on a plasmid of ~9 kb in porcine E. faecalis isolates, and of erm(B) and tet(O) on a low-molecular-weight plasmid of ~11 kb in poultry E. faecalis isolates. Furthermore, we demonstrated, through mating experiments, these plasmids could be transferred. Results indicate that the intestinal enterococci of healthy pigs and poultry, which can contaminate meat at slaughter, could be a reservoir for quinupristin-dalfopristin, bacitracin, tetracycline, and macrolide resistance genes. To assess the use of a polyclonal antiserum AS on the contact interference of a high level bacitracin resistant (bcrRAB genes) pheromone-responsive plasmid, a multiresistant E. faecalis isolate of poultry origin was selected. After induction with pheromones produced by the recipient strain E. faecalis JH2-2, clumping of the donor E. faecalis strain 543 was demonstrated as well as high transfer frequencies in short time broth mating. Conjugative transfer of asa1, traB and bcrRAB genes and their co-localization were also demonstrated in the donor strain and a transconjugant T543-1 on a plasmid band of 115 kb by PFGE and Southern blotting. A MIC to bacitracin of > 2 048 µg/ml was obtained for both strains 543 and T543-1 whereas the recipient strain JH2-2 demonstrated a MIC of 32 µg/ml. Sequencing of the asa1 gene encoding for an AS, and traB for a pheromone shutdown protein, confirmed the association of this genetic element to the pheromone-responsive plasmid related to pJM01. More significantly, this study presents the evidence that a polyclonal antiserum AS can significantly interfere with the horizontal transfer of a pheromone-responsive plasmid encoding high-level bacitracin resistance of a poultry multidrug resistant E. faecalis strain. Clinical isolates of E. faecium of human and canine origin were analyzed and compared. This report describes for the first time the characterization of canine clinical ampicillin-resistant E. faecium (AREF) isolates related to CC17 (ST17) in Canada. These isolates were resistant to ciprofloxacin and lincomycin. Resistance to ciprofloxacin was confirmed by amino acid substitutions in DNA gyrase (gyrA/gyrB) and topoisomerase IV (parC/parE) genes. High-level gentamicin, -kanamycin and -streptomycin resistances and macrolides resistance were also observed. The frequency of tetracycline resistance was high whereas vancomycin resistance was not detected. Also, no resistance was observed to linezolid and quinupristin-dalfopristin antibiotics. Data demonstrated the complete absence of enterococcal surface protein (esp) and hyaluronidase (hyl) genes among the canine AREF isolates tested while all were acm (collagen adhesin from E. faecium) positive. However, most of them were shown to harbor efaAfm gene, encoding for a cell wall adhesin. No biofilm formation or clustered regularly interspaced short palindromic repeats (CRISPR) elements were identified in these canine AREF isolates. rep6 and rep11 families of plasmids were significantly associated with isolates from dogs. The PFGE patterns of human and dog isolates were considered unrelated (≤ 80%). These findings also support the importance of prudent use of antibiotics in veterinary medicine to avoid zoonotic spread of canine AREF isolates. We are confident that our results may help to better understand the mechanisms of antibiotic resistance and mobile element carrying them as well as new strategies to reduce the horizontal transfer of antibiotic resistance and virulence traits.

Uma infecção pulpar pode resultar na colonização microbiana de todo sistema de canais radiculares incluindo os túbulos dentinários. Estes microorganismos e seus produtos tóxicos são responsáveis pelo desenvolvimento e persistência da periodontite apical de origem endodôntica. O presente estudo objetivou avaliar a viabilidade de E. faecalis e C. albicans em túbulos dentinários após a aplicação de hidróxido de cálcio, clorexidina gel 2%, hidróxido de cálcio associado à clorexidina gel 2% e soro fisiológico, através da análise por cultura microbiológica e microscopia de fluorescência. Para tanto 120 raízes de dentes humanos foram padronizadas e autoclavadas, sendo posteriormente divididas em 2 grupos (n= 60) para contaminação com E. faecalis e C. albicans por 21 dias. Em seguida, foram divididas em 8 grupos (n= 15) para aplicação das substâncias antimicrobianas nos canais radiculares e posterior incubação em estufa por 14 dias. Amostras da dentina radicular na extensão de 0 - 100 µm e de 100 - 200 µm foram coletadas e submetidas à cultura microbiológica através do plaqueamento em meios de cultura. Após 48 horas de incubação promoveu-se a avaliação das UFC. Paralelamente, as amostras foram processadas para análise em microscopia de fluorescência com auxílio de marcadores fluorescentes específicos, a fim de se determinar a proporção de microorganismos viáveis e não viáveis. Outros 6 espécimes foram preparados para análise em MEV. Os resultados mostraram uma maior capacidade de penetração intratubular para E. faecalis quando comparado a C. albicans. A aplicação de medicação intracanal resultou em significativa redução da viabilidade dos microorganismos quando comparado ao grupo controle independente da medicação aplicada e em ambas as porções da dentina radicular avaliadas. Entretanto, ao compararmos individualmente as medicações, observamos o melhor desempenho da clorexidina gel 2 % e da associação de hidróxido de cálcio e clorexidina gel 2% sem diferença significante entre elas. O hidróxido de cálcio apresentou os piores resultados para desinfecção dos canais radiculares contaminados com E. faecalis e C. albicans. Estes achados foram confirmados tanto pela cultura microbiológica quanto pela microscopia de fluorescência. A cultura microbiológica e a microscopia de fluorescência são métodos adequados e complementares para avaliação da viabilidade de E. faecalis e C. albicans e a eficácia da clorexidina gel 2% e da associação hidróxido de cálcio e clorexidina gel 2% justificam seu uso em endodontia como medicação intracanal. / A pulp infection can result in a microbial colonization of the entire root canals system, including dentinal tubules. These microorganisms and their toxic product are responsible for the development and persistence of apical periondontitis from endodontic source. The present study aimed to evaluate E. faecalis and C. albicans viability in dentinal tubules after the application of calcium hydroxide, chlorhexidine gel 2%, calcium hydroxide associated to chlorhexidine gel 2% and physiological solution, through the analysis by microbiological culture and fluorescence microscopy. For that, 120 human teeth root were standardized and submitted to autoclave, and after ere divided into 2 groups (n=60) for E. faecalis and C. albicans contamination for 21 days. Following this, they were divided into 8 groups (n=15) for application of antimicrobial substances in the root canals and subsequent incubation for 14 days. Samples from root dentin with 0 - 100 µm and 100 - 200 µm of extension were collected and submitted to microbiological culture.After 48 hours of incubation, it was performed the evaluation of colony-forming units (CFU). At the same time, the samples were processed for fluorescence microscopic analysis with the assistance of specific fluorescent markers, in order to determine the proportion of viable and non-viable microorganisms. Other 6 specimens were prepared for the analysis of scanning electron microscopy. Results demonstrated a higher capacity of penetration in the tubules for E. faecalis than for C. albicans. The application of intracanal medication resulted in significant reduction of microorganisms viability when compared to the control groups independently of the medication used and in both evaluated portions of root dentin. However, when one compares individually the medications, it was observed a better performance of chlorhexidine gel 2% and the association of calcium hydroxide with chlorhexidine gel 2% without a significant difference between them. Calcium hydroxide had the worst results for disinfection of root canal contaminated with E. faecalis and C. albicans. These findings were confirmed for the microbiological culture as well as for the fluorescence microscopy. The microbiological culture and the fluorescence microscopy are adequate methods and complementary for the evaluation of E. faecalis and C. albicans viability and the efficacy of chlorhexidine gel 2% and the association of calcium hydroxide with chlorhexidine gel 2% warrant their use in Endodontics as an intracanal medication.

INTRODUÇÃO: Infecção do trato urinário (ITU) é doença cujos sinais e sintomas são frequentemente inespecíficos, especialmente em lactentes. Portanto, o conhecimento de seus aspectos epidemiológicos, clínicos e laboratoriais são relevantes para a adequada abordagem clínica. OBJETIVOS PRINCIPAIS: Descrever: a prevalência de ITU como motivo de atendimento em pronto-socorro geral de Pediatria; a variabilidade da frequência de ITU e dos agentes etiológicos em diversas faixas etárias e sexo; o perfil de sensibilidade antimicrobiana de Escherichia coli; o quadro clínico, laboratorial e evolutivo de lactentes jovens. OBJETIVOS SECUNDÁRIOS: Cálculo de sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo do corte de leucocitúria >= 10.000 leucócitos/mL para o diagnóstico de ITU em lactentes jovens. Comparar as diferenças de ITU por Escherichia coli e Staphylococcus saprophyticus em adolescentes do sexo feminino e discutir as melhores escolhas de terapia antimicrobiana empírica para uso na população estudada. MÉTODO: Estudo retrospectivo, descritivo, incluindo todos os casos de ITU (urocultura quantitativa com >= 50.000 UFC/mL por sondagem vesical ou >= 100.000 UFC/mL por jato médio) atendidos no Pronto-Socorro de Pediatria do Hospital Universitário da Universidade de São Paulo, de 01/01/2010 a 31/12/2012, idades entre zero a 15 anos incompletos. Resultados: Do total de 188.460 atendimentos realizados, 7994 colheram urocultura por suspeita de ITU; este diagnóstico foi confirmado em 1071 casos (prevalência: 0,57% do total de atendimentos e 13,4% das uroculturas incluídas). A proporção de casos entre sexo masculino e feminino foi: 1:0,3 em menores de três meses; 1:3,9 entre três meses a 12 anos e 1:12 entre 12 a 15 anos. Escherichia coli foi o principal agente responsável por 73,2% dos casos totais de ITU. Entretanto, outros agentes importantes foram Klebsiella pneumoniae (18,46%) e Enterococcus faecalis (7,7%) em lactentes jovens (menores de três meses de idade); Proteus mirabilis (30,8%) em meninos de três meses a 12 anos; Staphylococcus saprophyticus (25%) em adolescentes do sexo feminino entre 12 a 15 anos. A sensibilidade antimicrobiana de Escherichia coli foi observada acima de 80% para: amoxicilina/ácido clavulânico (87%), cefuroxima (98%), cefotaxima (98%), ceftriaxona (100%), cefepime (99%), amicacina (100%), gentamicina (97%), ciprofloxacina (98%), norfloxacina (94%), ácido nalidíxico (93%) e nitrofurantoína (97%). Em lactentes jovens, febre sem sinais localizatórios foi o sintoma mais frequente de ITU (77,8%). Exames subsidiários de hemograma e proteína C reativa foram de pouca utilidade clínica. O teste de nitrito positivo apresentou baixa sensibilidade: 30,8% (IC 95%: 19,9%-43,4%), porém elevada especificidade e valor preditivo positivo. Enquanto que o corte de leucocitúria > 10.000 leucócitos/mL para ITU revelou boa sensibilidade: 87,7% (IC 95%: 77,2%-94,5%), porém baixa especificidade e valor preditivo positivo. Nas adolescentes do sexo feminino entre 12 a 15 anos, houve menor positividade do teste do nitrito nas ITU por Staphylococcus saprophyticus do que nas ITU por Escherichia coli. Na população do presente estudo, a terapia empírica inicial recomendada seria: zero a três meses: tratamento parenteral com aminoglicosídeo ou cefalosporina de terceira geração; podendo associar ampicilina para cobertura de Enterococcus faecalis. Entre três meses a 15 anos: amoxicilina/ácido clavulânico ou cefuroxima ou ceftriaxona ou aminoglicosídeos. CONCLUSÕES: ITU é doença frequente em atendimentos de pronto-socorro. Os aspectos epidemiológicos, clínicos e laboratoriais são variáveis nas diversas faixas etárias e sexos; portanto, a abordagem deve ser individualizada em cada um destes segmentos / INTRODUCTION: Urinary tract infection (UTI) frequently presents with nonspecific signs and symptoms, particularly in infants. Therefore, the understanding of its epidemiological, clinical and laboratory aspects are relevant to its appropriate clinical approach. MAIN OBJECTIVES: To describe: the prevalence of UTI as a cause for attending the pediatric emergency department; the variability of the frequency of UTI and etiological agents in different age groups and sexes; the antimicrobial sensitivity profile of Escherichia coli; the clinical features, laboratory findings and treatment outcomes in young infants. SECONDARY OBJECTIVES: To evaluate sensitivity, specificity, positive predictive value and negative predictive value of pyuria >= 10,000 leukocytes/mL for screening UTI in young infants. To compare UTI due to Escherichia coli with UTI due to Staphylococcus saprophyticus in female adolescents and to discuss the best empirical antimicrobial treatment in the population studied. METHODS: Retrospective, descriptive study, including all cases of UTI (urine culture of >= 50,000 CFU/mL obtained by bladder catheterization or >= 100,000 CFU/mL obtained by midstream-voided method) attended at the pediatric emergency department of University Hospital of the University of São Paulo, from 01/01/2010 to 12/31/2012, ages from zero to 15 years old. Results: Of 188,460 visits in this period, 7994 collected urine culture on suspicion of UTI. This diagnosis was confirmed in 1071 cases (prevalence: 0.57% of total visits and 13.4% of urine cultures included). The proportion of cases between male and female was: 1: 0.3 in children younger than three months old; 1: 3.9 from three months to 12 years old and 1:12 from 12 to 15 years old. Escherichia coli was the main etiology responsible for 73.2% of total cases of UTI. However, other important agents were Klebsiella pneumoniae (18.46%) and Enterococcus faecalis (7.7%) in young infants (under three months of age); Proteus mirabilis (30.8%) in boys from three months to 12 years old; Staphylococcus saprophyticus (25%) in female adolescents aged 12-15 years. The antimicrobial sensitivity of Escherichia coli was still above 80% for amoxicillin / clavulanic acid (87%), cefuroxime (98%), cefotaxime (98%), ceftriaxone (100%), cefepime (99%), amikacin (100%), gentamicin (97%), ciprofloxacin (98%), norfloxacin (94%), nalidixic acid (93%) and nitrofurantoin (97%). In young infants, the absence of another source of fever was the most frequent UTI symptom (77.8%). Laboratory parameters including peripheral white blood cell count and C-reactive protein concentration were of limited clinical usefulness. The sensitivity of nitrite testing for bacteriuria was low: 30.8% (95% CI: 19.9%-43.4%), but had high specificity and positive predictive value. Pyuria> 10,000 leukocytes / mL for identifying UTI had high sensitivity: 87.7% (95% CI: 77.2%-94.5%), but low specificity and positive predictive value. In female adolescents aged 12 to 15 years old, there were few positive nitrite tests in UTI due to Staphylococcus saprophyticus compared with UTI due to Escherichia coli. In the population studied, the initial empirical therapy recommended would be: from zero to three months old: parenteral treatment with aminoglycoside or third generation cephalosporin; it could be associated with ampicillin to treat Enterococcus faecalis. Between three months to 15 years old: amoxicillin / clavulanic acid or cefuroxime or ceftriaxone or aminoglycosides. In cystitis: in addition to amoxicillin / clavulanic acid or cefuroxime; nitrofurantoin is also a good option for Staphylococcus saprophyticus UTI whereas nalidixic acid is also a nice choice for Proteus mirabilis UTI. CONCLUSIONS: UTI is a common disease in emergency department visits. The epidemiological, clinical and laboratory aspects are variable in the different age and sex groups; therefore, the approach must be individualized in each of these groups

O objetivo deste estudo foi avaliar os efeitos da irradiação do canal radicular pelo laser de diodo, quando associado à terapêutica endodôntica tradicional: no aumento da temperatura na superfície radicular externa; nas alterações morfológicas da dentina do canal radicular; no selamento marginal apical após obturação do canal radicular e no potencial de redução microbiana. O aumento de temperatura foi monitorado durante a irradiação do canal radicular de incisivos inferiores por câmera termográfica. Os parâmetros de irradiação foram: grupo de emissão contínua (CW): P=2,5 W e grupo de emissão pulsada ?P=1,25 W. A avaliação das alterações morfológicas por MEV das amostras irradiadas nas condições acima citadas foram comparadas com amostras não irradiadas. O grau de infiltração marginal apical foi mensurado em amostras irradiadas (CW; P = 2,5 W) ou não irradiadas, e obturadas por um dos três cimentos endodônticos: N-Rickert, AH Plus ou Apexit. O grau de penetração linear foi medido após o período de imersão das amostras na solução de azul de metileno. O potencial de redução microbiana promovido pela associação do laser à terapêutica endodôntica tradicional foi avaliado em dentes portadores de infecção endodôntica primária por técnicas de cultura e PCR. A irrigação de NaOCl 0,5 % e uso de hidróxido de cálcio (grupo controle) foram associados à irradiação no grupo laser (CW; P=2,5 W). Foram avaliadas: a redução do número de UFC dos anaeróbios viáveis, a quantidade de E. faecalis e de lactobacilos/amostra, e a proporção de E. faecalis e de lactobacilos/microrganismos viáveis. O aumento de temperatura na superfície radicular externa durante a irradiação do canal radicular nos regimes de emissão contínuo e pulsado não excedeu o limite crítico de 10 ºC. A variação de 10 temperatura mediana máxima na região apical usando o método de Wilcoxon (p < 0,05) foi de 8,6 °C na irradiação contínua e de 3,3 °C na emissão pulsada. O tempo de resfriamento de 20 segundos foi determinado entre os 5 ciclos de irradiação. As alterações morfológicas promovidas pela irradiação do canal revelaram fusão da dentina e obliteração dos túbulos dentinários especialmente no terço apical, em ambas as condições de irradiação. A irradiação do canal radicular pelo laser de diodo reduziu significativamente o grau de infiltração marginal apical nos canais obturados pelo cimento Apexit (Kruskal Wallis p < 0,05). A prevalência dos anaeróbios viáveis ao final do tratamento foi menor no grupo laser do que no grupo controle, embora não tivesse sido constatada diferença significante entre os grupos (Mann-Whitney p > 0,05). O porcentual de lactobacilos/microrganismos viáveis no início do tratamento foi 22 % reduzindo a zero ao final, no grupo controle. Esse microrganismo não foi detectado no grupo laser. A proporção de Enterococcus/microrganismos viáveis variou de 36 %-50 % no grupo controle, e 22 %-0 % no grupo laser, no início e final do tratamento, respectivamente. Nas condições testadas, os resultados sugerem que o laser de diodo mostrouse uma ferramenta possível de ser incorporada à Endodontia, contudo os efeitos biológicos são similares à terapêutica endodôntica tradicional bem executada. / The aim of this study was to evaluate the effects of diode laser irradiation associated with endodontic therapy. The aspects analyzed were: temperature rise at the external root surface, morphological changes at the dentine root walls, apical marginal leakage after root sealing, and microbiological reduction after laser irradiation. The temperature rise in inferior incisor teeth was monitored using a thermographic camera. Two laser treatment parameters were investigated: continuous emission mode (CW) with P = 2.5 W and pulsed emission mode (PL) with average power?P = 1.25 W. The morphological changes of irradiated samples were analyzed by SEM for both treatment modes and compared with a non-irradiated control group. The apical marginal leakage was measured after the immersion in methylene blue solution for irradiated (CW; P = 2.5 W) and non-irradiated samples sealed by one of the following endodontic sealers: N-Rickert, AH Plus or Apexit. The reduction in microbiological activity after conventional endodontic therapy and after laser irradiation was evaluated in primary endodontic infection using culture and PCR techniques, where the control group used conventional 0.5 % NaOCl solution and calcium hydroxide treatment was compared with laser irradiation (CW; P = 2.5 W). The reduction of viable anaerobic microorganisms, the quantity of E. faecalis and Lactobacillus per samples, and the rate of E. faecalis and Lactobacillus per viable microorganism were analyzed. The temperature rise at external root surface during root canal irradiation in both continuous and pulsed emission modes was demonstrated not exceed the safety limit of 10 ºC. The maximum median temperature variation was 8.6 °C (CW) at the continuous emission mode and 1.6 °C at pulsed mode (PL) (Wilcoxon, p < 0.05). The optimal ?resting time? between each of five irradiation cycles was 12 determined to be 20 seconds to allow for tissue cooling and hence to prevent potential dangerous rises in the tissue temperature. SEM analysis revealed melting of dentine and closure of dentinal tubules especially at apical third for both irradiation conditions. The apical marginal leakage was significant reduced in the irradiated samples sealed with Apexit (Kruskal Wallis, p < 0.05). The prevalence of the viable anaerobic microorganisms exhibited reduced with time in both the control and laser groups with no statistical difference (Mann-Whitney p > 0.05). The Lactobacillus rate per viable microorganisms in the control group was 22 % at the beginning of the treatment and decreasing to zero at the end. This microorganism was not detected in laser group. The rate of Enterococcus per viable microorganism ranged 36 % to 50 % in the control group and 22 % to 0 % in laser group at the begin and the end of treatments, respectively. The conclusion is that diode laser technology is suitable for applications in endodontic therapy under the conditions tested in this study, however, the biological effects are similar to well done conventional endodontic therapy.