Enterococcus species are integral members of the gastrointestinal microfloral of humans, animals, birds, as well as insects. Their presence in water and food has been greatly associated with faecal contamination. This study was aimed at evaluating the incidence of Enterococcus species in cow dung and environmental water sources in three commercial dairy farms. In addition, their antibiotic profiles were determined as well as resistance and virulence genes. Furthermore, the genetic relatedness of the isolates was determined by molecular typing method (RAPD PCR). Three hundred and thirty four water and faecal samples consisting of 117, 116 and 101 were collected from Seven Star Middle Drift and Fort Hare Dairy trusts respectively. Of the 334 samples collected, 289 were of faecal origin and 45 from water sources within the farms. All samples were screened for enterococci using culture base growth media and molecular methods targeting the tuf gene. Speciation was done using species-specific primers and the incidences of various species within the farms determined. Furthermore resistance to antibiotics and multidrug-resistant phenotypes were established using the disk diffusion method. Genes coding for virulence and resistance were also determined. From the samples collected, 313 (289 faecal and 24 water) presumptive enteroccocci were isolated, 305 of 313 (97.45 percent) were confirmed as Enterococcus of which 239 of 305 (78.38 percent) were identified as E. hirae, 15 of 305 (4.92 percent) as E. faecium, 12/305 (3.93 percent) as E. durans, 6 of 305 (1.97 percent) as E. faecalis and 33 of 305 (10.82 percent) were unidentified. Out of the five virulence genes that were targeted in the study only gelE (71.80 percent of 219/305) and ace (27.2 percent 83/305) were present in the isolates. Phenotypic resistance to antibiotics was observed is in all twelve antibiotics tested with multidrug resistance phenotypes detected in some enterococcal isolates most predominant in Seven Star and Middledrift dairy trust. Finally RAPD profiles of the isolates showed high relatedness between the strains from water and cow dung sources in all three commercial dairy farms suggesting possible contamination from cow dung to the water sources or vice versa.

Made available in DSpace on 2015-09-17T15:24:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-12-11. Added 1 bitstream(s) on 2015-09-17T15:47:23Z : No. of bitstreams: 1 000843125.pdf: 3415915 bytes, checksum: 3c3dc53c547494a401c76c5c860f02ab (MD5) / Enterococcus faecium se tornou um dos mais temidos micro-organismos em infecções hospitalares, por apresentar maior facilidade em adquirir resistência aos antibióticos do que E. faecalis. Entretanto, faltam estudos voltados para o isolamento e identificação de E. faecium na cavidade bucal. Os objetivos deste trabalho foram isolar e identificar E. faecalis e E. faecium em canais radiculares com infecções endodônticas e comparar as cepas de E. faecalis e E. faecium em relação à sensibilidade aos antibióticos convencionais e à terapia fotodinâmica antimicrobiana (PDT). Além disso, essas espécies foram comparadas quanto à virulência in vivo, utilizando o modelo de infecção experimental de Galleria mellonella. As cepas de E. faecalis e E. faecium isoladas de canais radiculares foram identificadas pelo sistema Rapid ID 32 Strep e PCR multiplex. Todos os isolados identificados como E. faecalis e E. faecium, foram testadas quanto à sensibilidade aos antibióticos pelo método E-test para determinação da concentração inibitória mínima (MIC). A seguir, foram selecionadas algumas cepas de E. faecalis e E. faecium sensíveis e resistentes aos antibióticos de uso clínico na odontologia para testes de sensibilidade in vitro à terapia fotodinâmica antimicrobiana. A virulência das cepas de E. faecalis e E. faecium foram testadas in vivo no modelo de infecção experimental de G. mellonella por meio da análise da curva de sobrevivência das larvas e quantificação de UFC/mL de células bacterianas presentes na hemolinfa desses animais. Os dados de UFC/mL obtidos na terapia fotodinâmica e na infecção em G. mellonella foram submetidos à análise de variância e teste de Tukey. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo método de Log-rank. Foram realizadas coletas de 38 canais radiculares de diferentes pacientes, sendo que 22 apresentaram culturas positivas para enterococcus spp.(58%).... / Enterococcus faecium has become one of the most dreaded micro-organisms in nosocomial infections, due to its greater ease in acquiring resistance to antibiotics than E. faecalis. However, lack of studies focused on the isolation and identification of E. faecium in the oral cavity. The objectives of this study was to isolate and identify E. faecalis and E. faecium in root canals with endodontic infections and to compare strains of E. faecalis and E. faecium in sensitivity to conventional antibiotics and antimicrobial photodynamic therapy (PDT). Furthermore, these species were compared for virulence in vivo, using the model of experimental infection of Galleria mellonella. The strains of E. faecalis and E. faecium isolated from root canals were identified by the Rapid ID 32 Strep system and multiplex PCR. All isolates identified as E. faecalis and E. faecium were tested for antibiotic susceptibility E-test method for determination of minimal inhibitory concentration (MIC). Next, we selected some strains of E. faecalis and E. faecium sensitive and antibiotic-resistant clinical use in dentistry for in vitro susceptibility testing to antimicrobial photodynamic therapy. The virulence of strains of E. faecalis and E. faecium were tested in in vivo experimental model of infection of G. mellonella by analysis of larval survival curve and quantitation of CFU/mL bacterial cells present in the hemolymph of these animals. Data from CFU/mL obtained in photodynamic therapy and infection in G. mellonella were subjected to analysis of variance and Tukey test. The data on the survival of G. mellonella curves were analyzed by log-rank method. Samples of 38 root canals from different patients were performed and 22 had cultures positive for Enterococcus spp. (58%). Of these patients, all showed E. faecalis and only 2 had mixed infections with E. faecalis and E. faecium 6 isolates (27%) E. faecalis resistant to ....

Made available in DSpace on 2014-12-02T11:16:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-17Bitstream added on 2014-12-02T11:21:07Z : No. of bitstreams: 1 000800633.pdf: 461044 bytes, checksum: f9c8483ec74aaeb69a13040e8c9352f2 (MD5) / O presente estudo avaliou a atividade antimicrobiana, escoamento, pH e a liberação de cálcio do MTA Fillapex (MTAF) (G1) ou MTA Fillapex com 10% (em massa) de hidróxido de cálcio (HC) (MTAF10) (G2), comparados com o AH Plus (AP) (G3) e o Sealapex (SE) (G4). A atividade antimicrobiana foi realizada através de teste de difusão radial sobre Enterococos faecalis (29212). O escoamento foi realizado de acordo com a norma ISO 6876:2001. Os cimentos foram inseridos em tubos de polietileno e imersos em recipiente com água deionizada. Após 24 horas, 7, 14 e 28 dias os valores do pH e cálcio liberado foram mensurados. Os valores obtidos na liberação de cálcio foram analisados através dos testes de Kruskal Wallis e Dunn e a atividade antimicrobiana, pH e escoamento foram analisados através dos testes de ANOVA e Tukey (p=0,05). A atividade antimicrobiana foi similar entre os cimentos (p>0,05). G1 e G2 apresentaram respectivamente o maior e menor escoamento que os demais grupos (p<0,05). G2 e G4 apresentaram pH e liberação de cálcio maior que G3 (p<0,05), em todos os períodos. G1 apresentou maior pH que G3 (p<0,05), exceto no período de 7 dias (p>0,05). G4 apresentou maior pH do que G1 e G2, mas o cálcio liberado foi similar (p>0,05). G3 apresentou menor liberação de cálcio entre todos os grupos (p<0,05). A adição de 10% de HC no MTAF não alterou o pH e liberação de cálcio do cimento e reduziu o escoamento, porém fora das padronizações técnicas. / This study evaluated the antimicrobial activity, flow, pH and calcium release of MTA Fillapex (MTAF) (G1) or MTA Fillapex plus 10% in weight of calcium hydroxide powder (CH) (MTAF10) (G2), compared to AH Plus (AP) (G3) and Sealapex (SE) (G4). The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and antimicrobial activity, pH values and flow were analyzed by ANOVA and Tukey tests (α = 5%). The antimicrobial activity was similar among all groups (p>0.05). G1 presented higher flow among all sealers (p<0.05). The addition of 10% CH into MTAF reduced the flow (p<0.05), but in discordance with ISO requirements. G2 and G4 presented pH values and calcium release higher than G3 (p<0.05), in all periods. G1 presented pH value higher than G3 (p<0.05), except in 7 days period (p>0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p>0.05). G3 presented lower calcium release among all groups (p<0.05). The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. The flow obtained does not follow ISO requirements.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-09-05T20:18:57Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Renata Alexandre Ramos da Silva.pdf: 1250884 bytes, checksum: 0a138f281b993d44165f8bf1bdd9aa3e (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-14T19:48:59Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Renata Alexandre Ramos da Silva.pdf: 1250884 bytes, checksum: 0a138f281b993d44165f8bf1bdd9aa3e (MD5) / Made available in DSpace on 2018-09-14T19:48:59Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Renata Alexandre Ramos da Silva.pdf: 1250884 bytes, checksum: 0a138f281b993d44165f8bf1bdd9aa3e (MD5) Previous issue date: 2014-02-20 / CAPES / O objetivo deste trabalho foi avaliar a atividade antimicrobiana do citral, linalol e quatro antimicrobianos (ampicilina, gentamicina, linezolida e vancomicina) frente à dez cepas de Enterococcus faecalis cujo fenótipo de resistência fora previamente determinado pelo método de difusão em disco. Quatro cepas de Enterococcus faecalis (EF 07, EF 11, EF 13 e ATCC 51299) apresentaram resistência à vancomicina e foram selecionadas para o estudo de interação entre o citral e os quatros antimicrobianos o qual foi realizado pelo método checkerboard. Os critérios utilizados para avaliar a atividade sinérgica foram definidos pelo Índice de Concentração Inibitória Fracionada (FIC index). O citral foi o mais eficaz frente as cepas de Enterococcus faecalis avaliadas quando comparado ao linalol. Os valores do FIC index variaram de 0,5 a 0,125 sugerindo uma interação sinérgica para todas as associações exceto com gentamicina a qual se mostrou indiferente. Este estudo demonstrou que o citral associado à vancomicina foi capaz de reduzir os valores da concentração inibitória mínima deste último em 93,75%. Antimicrobianos beta lactâmicos e glicopeptídeos agem sinergicamente quando associados ao citral inibindo cepas de Enterococcus faecalis multirresistentes. / The purpose of this work has been to evaluate the antimicrobial activity of citral, linalol and four antimicrobials (ampicillin, gentamicin, vancomycin and linezolid) against ten Enterococcus faecalis strains whose resistance phenotype was previously determined by disc diffusion method. Four Enterococcus faecalis strains (EF 07, EF 11, EF 13 e ATCC 51299) present resistance to vancomycin, and they were selected to the interaction study between the citral and the four antimicrobials which was realized by checkerboard method. The criteria used to evaluate the synergistic activity were defined by fractional inhibitory concentration index (FIC index). The citral was the most effective against the Enterococcus faecalis strains evaluated when it was compared to linalol. The value of FIC index ranged from 0.5 to 0.125 suggesting a synergistic interaction to all associations except with gentamicin which showed indifferent. This study has demonstrated that the citral associated with vancomycin was able to reduce the values of the minimum inhibitory concentration of this latter in 93.75%. Beta lactam antimicrobials and glycopeptides act synergistically when combined with citral inhibiting multidrug-resistant Enterococcus faecalis strains.

Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista / “Evaluación de la actividad antibacteriana in vitro de nanopartículas de cobre frente a Enterococcus faecalis” Introducción La patología pulpar y periapical se origina de una infección bacteriana que invade el sistema de canales radiculares, dando una respuesta inmunoinflamatoria en el hospedero, la que posteriormente se traduce en la destrucción de los tejidos perirradiculares. Existen microorganismos que son capaces de resistir los procedimientos endodónticos, identificándose dentro de éstos a Enterococcus faecalis, responsable de fracasos de tratamiento y patología endodóntica persistente. Por esta razón, existe la medicación intracanal, la cual pretende eliminar microorganismos remanentes, dejando un agente antimicrobiano entre sesiones clínicas. En la actualidad, el medicamento más efectivo y comúnmente usado, es el hidróxido de calcio. Sin embargo, se ha observado que esta bacteria, en algunos casos, no es susceptible a su acción antimicrobiana. Las nanopartículas metálicas, como las de cobre, aparecen como una nueva alternativa de antimicrobianos, cuyo efecto ya ha sido demostrado contra algunos microorganismos orales, tales como Aggregatibacter actinomycetemcomitans, Candida albicans y Streptococcus mutans. Sin embargo, no existen referencias de estudios frente a patógenos endodónticos. En el presente proyecto, se propone estudiar la actividad antibacteriana de las nanopartículas de cobre frente a Enterococcus faecalis. Materiales y métodos Se determinó la concentración mínima inhibitoria y concentración mínima bactericida de nanopartículas de cobre frente a Enterococcus faecalis, a partir del método de macrodilución. Para evaluar la efectividad antimicrobiana intracanal, se contaminaron especímenes de dientes con Enterococcus faecalis y se procedió a medicar el canal radicular con nanopartículas de cobre a distintas concentraciones. Además, se utilizó como control un grupo con hidróxido de calcio y un tercer grupo sin medicamento. Dicha medicación se dejó por 1 y 7 días; posteriormente, se sembró y realizó recuento de unidades formadoras de colonias. Resultados Las nanopartículas de cobre presentaron acción antimicrobiana frente a Enterococcus faecalis in vitro, con valores de concentración mínima inhibitoria y concentración mínima bactericida de 150 ppm y 225 ppm, respectivamente. Al ser utilizadas como medicación intracanal en un modelo in vitro, su efecto antimicrobiano a 150 ppm y 300 ppm fue equivalente a la acción de Ultracal XS®. Observaciones mediante microscopía electrónica de barrido, demostraron que las nanopartículas de cobre, además de tener un efecto bactericida, remueven bacterias de la superficie radicular y alteran su morfología. Conclusiones Mediante la determinación de los valores de concentración mínima inhibitoria y concentración mínima bactericida, se comprobó la hipótesis de que las nanopartículas de cobre presentan actividad antimicrobiana frente a la bacteria endodóntica Enterococcus faecalis. Al utilizar las nanopartículas de cobre como medicación en un modelo intracanal presentan una acción antimicrobiana equivalente a la presentada por Ultracal XS®. El Análisis por microscopía electrónica de barrido y microanálisis elemental por energía dispersiva de rayos x sugiere que además del mecanismo bactericida de las nanopartículas de cobre, tendrían una acción antimicrobiana removiendo el biofilm desde el sistema de canales radiculares mediante un efecto anti-fouling. Las actividad antimicrobiana presentada por las nanopartículas de cobre frente a Enterococcus faecalis sugiere que podría ser evaluada en el futuro como alternativa de agente antimicrobiano en procedimientos endodónticos. / Adscrito a Proyecto PRI-ODO 15-004.

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. / Tesis

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.

It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009

It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009

Thesis (M.S.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed on Sept. 3, 2009). Includes bibliographical references (p. 44-49).