Name: rose bengal-mediated photodynamic therapy to inhibit candida albicans
Uploaded: 2022-03-24T14:00:00
Description: Watch this Scientific Journal Video about Rose Bengal-Mediated Photodynamic Therapy to Inhibit Candida albicans at JoVE.com

Este trabajo ha recibido financiación del Centro de Nanomedicina Aplicada, Universidad Nacional Cheng Kung del Programa del Centro de Investigación de Áreas Destacadas en el marco del Proyecto Sprout de Educación Superior del Ministerio de Educación (MOE), y del Ministerio de Ciencia y Tecnología de Taiwán [MOST 109-2327-B-006-005] a TW Wong. J.H. Hung reconoce la financiación del Hospital Universitario Nacional Cheng Kung, Taiwán [NCKUH-11006018] y [MOST 110-2314-B-006-086-MY3].

1. Preparación del sistema aPDT
<ol><li>Corte cuatro diodos emisores de luz verde (LED) de una tira de LED (consulte la Tabla de materiales) y alinee con cuatro pocillos de una placa de 96 pocillos (Figura 1). NOTA: Los LED se organizaron en una matriz de 4 x 3. La parte posterior del LED se adhirió a un disipador de calor para dispersar el calor durante la irradiación.</li>
	<li>Mida la velocidad de fluencia11 del LED a 540 n...

<ol>
	<li>Naglik, J. R., Challacombe, S. J., Hube, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candida+albicans+secreted+aspartyl+proteinases+in+virulence+and+pathogenesis.">Candida albicans secreted aspartyl proteinases in virulence and pathogenesis.</a> Microbiology and Molecular Biology Reviews. 67 (3), 400-428 (2003).</li><li>Pappas, P. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+practice+guideline+for+the+management+of+candidiasis:+2016+update+by+the+Infectious+Diseases+Society+of+America.">Clinical practice guideline for the management of candidiasis: 2016 update by the Infectious Diseases Society of America.</a> Clinical Infectious Diseases. 62 (4), 1-50 (2016).</li><li>Ricotta, E. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invasive+candidiasis+species+distribution+and+trends,+United+States,+2009-2017.">Invasive candidiasis species distribution and trends, United States, 2009-2017.</a> Journal of Infectious Diseases. 223 (7), 1295-1302 (2021).</li><li>Koehler, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morbidity+and+mortality+of+candidaemia+in+Europe:+an+epidemiologic+meta-analysis.">Morbidity and mortality of candidaemia in Europe: an epidemiologic meta-analysis.</a> Clinical Microbiology and Infection. 25 (10), 1200-1212 (2019).</li><li>Toda, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Population-based+active+surveillance+for+culture-confirmed+candidemia+-+four+sites,+United+States,+2012-2016.">Population-based active surveillance for culture-confirmed candidemia - four sites, United States, 2012-2016.</a> Morbidity and Mortality Weekly Report Surveillance Summaries. 68 (8), 1-15 (2019).</li><li>Lee, C. N., Hsu, R., Chen, H., Wong, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Daylight+photodynamic+therapy:+an+update.">Daylight photodynamic therapy: an update.</a> Molecules. 25 (21), 5195 (2020).</li><li>Wainwright, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photodynamic+antimicrobial+chemotherapy+(PACT).">Photodynamic antimicrobial chemotherapy (PACT).</a> Journal of Antimicrobial Chemotherapy. 42 (1), 13-28 (1998).</li><li>Wong, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Indocyanine+green-mediated+photodynamic+therapy+reduces+methicillin-resistant+staphylococcus+aureus+drug+resistance.">Indocyanine green-mediated photodynamic therapy reduces methicillin-resistant staphylococcus aureus drug resistance.</a> Journal of Clinical Medicine. 8 (3), 411 (2019).</li><li>Kim, M. M., Darafsheh, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+sources+and+dosimetry+techniques+for+photodynamic+therapy.">Light sources and dosimetry techniques for photodynamic therapy.</a> Photochemistry and Photobiology. 96 (2), 280-294 (2020).</li><li>Wong, T. W., Sheu, H. M., Lee, J. Y., Fletcher, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photodynamic+therapy+for+Bowen's+disease+(squamous+cell+carcinoma+in+situ)+of+the+digit.">Photodynamic therapy for Bowen's disease (squamous cell carcinoma in situ) of the digit.</a> Dermatologic Surgery. 27 (5), 452-456 (2001).</li><li>Wong, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photodynamic+inactivation+of+methicillin-resistant+Staphylococcus+aureus+by+indocyanine+green+and+near+infrared+light.">Photodynamic inactivation of methicillin-resistant Staphylococcus aureus by indocyanine green and near infrared light.</a> Dermatologica Sinica. 36 (1), 8-15 (2018).</li><li>Stasko, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visible+blue+light+inhibits+infection+and+replication+of+SARS-CoV-2+at+doses+that+are+well-tolerated+by+human+respiratory+tissue.">Visible blue light inhibits infection and replication of SARS-CoV-2 at doses that are well-tolerated by human respiratory tissue.</a> Scientific Reports. 11 (1), 20595 (2021).</li><li>Crosbie, J., Winser, K., Collins, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+the+light+field+of+the+Waldmann+PDT+1200+lamp:+potential+for+wide-field+low+light+irradiance+aminolevulinic+acid+photodynamic+therapy.">Mapping the light field of the Waldmann PDT 1200 lamp: potential for wide-field low light irradiance aminolevulinic acid photodynamic therapy.</a> Photochemistry and Photobiology. 76 (2), 204-207 (2002).</li><li>Feenstra, R. P., Tseng, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+fluorescein+and+rose+bengal+staining.">Comparison of fluorescein and rose bengal staining.</a> Ophthalmology. 99 (4), 605-617 (1992).</li><li>Demidova, T. N., Hamblin, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+cell-photosensitizer+binding+and+cell+density+on+microbial+photoinactivation.">Effect of cell-photosensitizer binding and cell density on microbial photoinactivation.</a> Antimicrobial Agents and Chemotherapy. 49 (6), 2329-2335 (2005).</li><li>Shahid, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Duclauxin+derivatives+from+fungi+and+their+biological+activities.">Duclauxin derivatives from fungi and their biological activities.</a> Frontiers in Microbiology. 12, 766440 (2021).</li><li>Arendrup, M. C., Park, S., Brown, S., Pfaller, M., Perlin, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+CLSI+M44-A2+disk+diffusion+and+associated+breakpoint+testing+of+caspofungin+and+micafungin+using+a+well-characterized+panel+of+wild-type+and+fks+hot+spot+mutant+Candida+isolates.">Evaluation of CLSI M44-A2 disk diffusion and associated breakpoint testing of caspofungin and micafungin using a well-characterized panel of wild-type and fks hot spot mutant Candida isolates.</a> Antimicrobial Agents and Chemotherapy. 55 (5), 1891-1895 (2011).</li><li>Mukaremera, L., Lee, K. K., Mora-Montes, H. M., Gow, N. A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candida+albicans+yeast,+pseudohyphal,+and+hyphal+morphogenesis+differentially+affects+immune+recognition.">Candida albicans yeast, pseudohyphal, and hyphal morphogenesis differentially affects immune recognition.</a> Frontiers in Immunology. 8, 629 (2017).</li><li>Hung, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+photodynamic+therapy+against+fungal+keratitis.">Recent advances in photodynamic therapy against fungal keratitis.</a> Pharmaceutics. 13 (12), 2011 (2021).</li><li>Martinez, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rose+Bengal+photodynamic+antimicrobial+therapy:+a+pilot+safety+study.">Rose Bengal photodynamic antimicrobial therapy: a pilot safety study.</a> Cornea. 40 (8), 1036-1043 (2021).</li></ol>

Recientemente se han reportado resultados alentadores de aplicaciones clínicas de RB-PDT para la queratitis fúngica19. El pico de absorción de RB está en 450-650 nm. Es esencial determinar la tasa de fluencia de la fuente de luz para una aPDT exitosa. Se requiere una fluencia alta (generalmente >100 J/cm2) para tratar las células cancerosas, mientras que se espera una fluencia más baja para tratar las lesiones infectadas6. Una alta fluencia significa un lar...

C. albicans coloniza en los tractos gastrointestinal y genitourinario de individuos sanos y puede detectarse como microbiota normal en aproximadamente el 50 por ciento de los individuos1. Si se crea un desequilibrio entre el huésped y el patógeno, C. albicans es capaz de invadir y causar enfermedades. La infección puede variar desde infecciones locales de la membrana mucosa hasta insuficiencia orgánica múltiple2. En un estudio de vigilancia multicéntrico en los Estados Unidos, alrededor de la mitad de los aislamientos de pacientes con candidiasis invasiva entre 2009 y 2017 es C. albicans3. La candidemia puede asociarse con altas tasas de morbilidad, mortalidad, estancia hospitalaria prolongada4. Los Centros para el Control y la Prevención de Enfermedades de los Estados Unidos informaron que aproximadamente el 7% de todas las muestras de sangre de Candida analizadas son resistentes al medicamento antimicótico fluconazol5. La aparición de especies de Candida resistentes a los medicamentos plantea la preocupación de desarrollar una terapia alternativa o adyuvante a los agentes antimicóticos.
La terapia fotodinámica antimicrobiana (aPDT) consiste en activar un fotosensibilizador (PS) específico con luz en la longitud de onda de absorción máxima de la PS6. Después de la excitación, el PS excitado transfiere su energía o electrones a las moléculas de oxígeno cercanas y regresa al estado fundamental. Durante este proceso, se forman especies reactivas de oxígeno y oxígeno singlete y causan daño celular. La aPDT se ha utilizado ampliamente para matar microorganismos desde la década de 19907. Uno de los beneficios de la aPDT es que múltiples orgánulos se dañan en una célula por oxígeno singlete y / o especies reactivas de oxígeno (ROS) durante la irradiación; por lo tanto, la resistencia a la APDT no se ha encontrado hasta hoy. Además, un estudio reciente informó que las bacterias que sobrevivieron después de la aPDT se volvieron más sensibles a los antibióticos8.
Las fuentes de luz utilizadas en aPDT incluyen láseres, lámparas halógenas de metal con filtros, luz infrarroja cercana y diodo emisor de luz (LED)9,10,11,12. El láser proporciona una alta potencia de luz, generalmente mayor que 0,5 W / cm2, que permite la entrega de una dosis de luz alta en muy poco tiempo. Se ha utilizado ampliamente en los casos en que un tiempo de tratamiento más largo es inconveniente, como la APDT para las infecciones orales. El inconveniente de un láser es que su tamaño de punto de iluminación es pequeño, que va desde unos pocos cientos de micrómetros hasta 10 mm con un difusor. Además, los equipos láser son caros y necesitan capacitación específica para operar. Por otro lado, el área de irradiación de una lámpara halógena de metal con filtros es relativamente más grande13. Sin embargo, la lámpara es demasiado pesada y cara. Las fuentes de luz LED se han convertido en la corriente principal de aPDT en el campo dermatológico porque es pequeña y menos costosa. El área de irradiación puede ser relativamente grande con una disposición de matriz de la bombilla LED. Toda la cara se puede iluminar al mismo tiempo9. Sin embargo, la mayoría, si no todas, las fuentes de luz LED disponibles hoy en día están diseñadas para uso clínico. Puede que no sea adecuado para experimentos en un laboratorio porque ocupa espacio y es costoso. Desarrollamos una matriz de LED económica que es muy pequeña y se puede cortar y ensamblar a partir de una tira de LED. Los LED se pueden instalar en diferentes arreglos para diferentes diseños experimentales. Se pueden completar diferentes condiciones de aPDT en una placa de 96 pocillos o incluso una placa de 384 pocillos en un experimento.
Rose bengal (RB) es un tinte de color ampliamente utilizado para mejorar la visualización de los daños corneales en los ojos humanos14. La aPDT mediada por RB ha demostrado efectos asesinos sobre Staphylococcus aureus, Escherichia coli y C. albicans con una eficiencia aproximadamente comparable a la del azul de toluidina O15. Este estudio demuestra un método para validar el efecto de RB-aPDT sobre C. albicans multirresistente.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1.5 mL microfuge tube</td>
			<td>Neptune, San Diego, USA</td>
			<td>#3745.x</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL round-bottom tube with cell strainer cap</td>
			<td>Falcon, USA</td>
			<td>#352235</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well plate</td>
			<td>Alpha plus, Taoyuan Hsien, Taiwan</td>
			<td>#16196</td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum foil</td>
			<td>sunmei, Tainan, Taiwan</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum heat sink</td>
			<td>Nanyi electronics Co., Ltd., Tainan, Taiwan</td>
			<td>BK-T220-0051-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf, UK</td>
			<td>5415R</td>
			<td>disperses heat from the LED array</td>
		</tr>
		<tr>
			<td>Graph pad prism software</td>
			<td>GraphPad 8.0, San Diego, California, USA</td>
			<td></td>
			<td>graphing and statistics software</td>
		</tr>
		<tr>
			<td>Green light emitting diode (LED) strip</td>
			<td>Nanyi electronics Co., Ltd., Tainan, Taiwan</td>
			<td>2835</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>Yihder, Taipei, Taiwan</td>
			<td>LM-570D (R)</td>
			<td>Emission peak wavelength: 525 nm, Viewing angle: 150&#176;; originated from https://www.aliva.com.tw/product.php?id=63</td>
		</tr>
		<tr>
			<td>Light power meter</td>
			<td>Ophir, Jerusalem, Israel</td>
			<td>PD300-3W-V1-SENSOR,</td>
			<td></td>
		</tr>
		<tr>
			<td>Millex 0.22 &#956;m filter</td>
			<td>Merck, NJ, USA</td>
			<td>SLGVR33RS</td>
			<td></td>
		</tr>
		<tr>
			<td>Multidrug-resistant Candida albicans</td>
			<td>Bioresource Collection and Research CenterBioresource, Hsinchu, Taiwan</td>
			<td>BCRC 21538/ATCC 10231</td>
			<td>http://catalog.bcrc.firdi.org.tw/BcrcContent?bid=21538</td>
		</tr>
		<tr>
			<td>OD600 spectrophotometer</td>
			<td>Biochrom, London, UK</td>
			<td>Ultrospec 10</td>
			<td></td>
		</tr>
		<tr>
			<td>Rose Bengal</td>
			<td>Sigma-Aldrich, MO, USA</td>
			<td>330000</td>
			<td>stock concentration 40 mg/mL = 4%, prepare in PBS, stored at 4 &#176;C</td>
		</tr>
		<tr>
			<td>Sterilized glass tube</td>
			<td>Sunmei Co., Ltd., Tainan, Taiwan</td>
			<td>AK45048-16100</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast Extract Peptone Dextrose Medium</td>
			<td>HIMEDIA, India</td>
			<td>M1363</td>
			<td></td>
		</tr>
	</tbody>
</table>

rose bengal-mediated photodynamic therapy to inhibit candida albicans

La infección invasiva por Candida albicans es una infección fúngica oportunista significativa en humanos porque es uno de los colonizadores más comunes del intestino, la boca, la vagina y la piel. A pesar de la disponibilidad de medicamentos antimicóticos, la tasa de mortalidad de la candidiasis invasiva sigue siendo de ~ 50%. Desafortunadamente, la incidencia de C. albicans resistente a los medicamentos está aumentando a nivel mundial. La terapia fotodinámica antimicrobiana (aPDT) puede ofrecer un tratamiento alternativo o adyuvante para inhibir la formación de biopelículas de C. albicans y superar la resistencia a los medicamentos. La aPDT mediada por rosa de bengala (RB) ha demostrado una eliminación celular efectiva de bacterias y C. albicans. En este estudio, se describe la eficacia de RB-aPDT en C. albicans multirresistente . Una fuente de luz de diodo emisor de luz verde (LED) casera está diseñada para alinearse con el centro de un pozo de una placa de 96 pocillos. Las levaduras se incubaron en los pozos con diferentes concentraciones de RB y se iluminaron con diferentes fluencias de luz verde. Los efectos de matanza se analizaron mediante el método de dilución de placas. Con una combinación óptima de luz y RB, se logró la inhibición del crecimiento de 3 log. Se concluyó que RB-aPDT podría inhibir potencialmente la C. albicans resistente a los medicamentos.

La Figura 1 muestra el sistema aPDT que se está utilizando en el presente estudio. Dado que las altas temperaturas pueden causar una muerte celular significativa, la matriz de LED se enfría mediante un ventilador eléctrico y se utiliza un disipador de calor durante la irradiación para mantener una temperatura constante a 25 ± 1 ° C. El efecto calor se puede descontar. Tener una distribución uniforme de la luz también es un factor determinante importante para un aPDT exitoso; por lo ...

Watch this Scientific Journal Video about Rose Bengal-Mediated Photodynamic Therapy to Inhibit Candida albicans at JoVE.com

Rose Bengal-Mediated Photodynamic Therapy to Inhibit Candida albicans

La creciente incidencia de Candida albicans resistente a los medicamentos es un grave problema de salud en todo el mundo. La terapia fotodinámica antimicrobiana (aPDT) puede ofrecer una estrategia para luchar contra las infecciones fúngicas resistentes a los medicamentos. El presente protocolo describe la eficacia de la aPDT mediada por Rose bengal en una cepa de C. albicans multirresistente in vitro.

Terapia fotodinámica mediada por rosa de Bengala para inhibir Candida albicans

Invasive Candida albicans infection is a significant opportunistic fungal infection in humans because it is one of the most common colonizers of the gut, ...

Este estudio es un sistema simple, versátil y fácil para examinar diferentes efectos fotodinámicos en diversos microorganismos y células. En este sistema, el LED se puede encajar en diferentes disposiciones dependiendo del diseño del experimento. Se pueden calcular diferentes condiciones de PDT en una placa de 96 pocillos o incluso en una placa de 384 pocillos en un experimento.Esta técnica se puede utilizar para tratar la queratitis fúngica debido a que a nivel mundial, alrededor de 150.000 personas pierden los ojos a pesar de los tratamientos intensivos. Para comenzar, corte cuatro LED verdes de una tira de LED y alinee con tres pocillos de una placa de 96 pocillos. Mida la velocidad de fluencia del LED a 540 nanómetros con un medidor de potencia de luz.Mantenga la temperatura constante a 25 grados centígrados con un ventilador eléctrico que se ensambló junto a la placa durante la irradiación. Con un lazo estéril, elija una sola colonia de Candida albicans de una placa de agar y agréguela a un tubo de vidrio esterilizado que contenga tres mililitros de medio YPD. Incubar el tubo a 25 grados Centígrados a una velocidad de rotación de 155 RPM durante 14 a 16 horas para cultivar el cultivo de levadura.A continuación, diluya el cultivo nocturno con YPD medio a un valor OD 600 de 0.5. Incubar a 30 grados centígrados con rotación a 155 RPM durante cuatro horas para lograr la fase de crecimiento logarítmico. Repetir la dilución del cultivo en fase logarítmica con medio YPD fresco a un valor de OD 600 de 0,65, para obtener aproximadamente una vez 10 a la séptima colonia formando unidades por mililitro.Prepare simultáneamente una solución de 4% de stock de rosa de bengala en 1X PBS. Esterilizar el filtro con un filtro de 0,22 micrómetros. Agregue 111 microlitros de solución de bengala de rosa al 2% a un mililitro de cultivo en fase logarítmica, y cocultivo en diferentes puntos de tiempo a temperatura ambiente para comprender la absorción de RB en las células.Centrifugar a 16, 100 veces G durante 2 1/2 minutos a temperatura ambiente, y lavar el cocultivo tres veces con un mililitro de 1X PBS. Después del lavado, vuelva a suspender el cultivo de Candida albicans en un mililitro de 1X PBS. Para cada condición, distribuya el cultivo en tres pozos diferentes en una placa de 96 pocillos.Alinee los pozos con la matriz de LED. En los grupos expuestos a la luz, encienda el ventilador eléctrico y la luz. Después de la irradiación, realice diluciones en serie diez veces dos veces tomando 20 microlitros de la solución de cocultivo de un pozo y agregándola a un tubo que contenga 180 microlitros de 1X PBS.Luego deje caer 20 microlitros de cada dilución en serie en un cuadrante de una placa de agar YPD para obtener colonias contables en la placa. La microscopía fluorescente mostró tinción inmediata de Candida albicans con rosa de bengala bajo fluorescencia roja. Después de 15 minutos de incubación, la mayoría de las células se tiñeron con rosa de bengala, lo que indica que ingresa a las células de una manera dependiente del tiempo.Además, la activación de la rosa de bengala con luz genera radicales libres y oxígeno singlete en las células, lo que resulta en la muerte celular. En ausencia de rosa de bengala o irradiación, no se observó muerte celular. Candida albicans se inhibió después de la irradiación de luz verde en presencia de 0,2% de bengala de rosa de una manera dependiente de la dosis de luz.Es importante que primero la placa de 96 pocillos esté alineada con el centro del LED. En segundo lugar, la placa de agar utilizada debe secarse bien para evitar la mezcla de colonias separadas. La Candida albicans que creció en la placa se puede enviar para el análisis de genes, que puede responder cómo la PDT afecta la expresión génica de las células.Estas técnicas allanan el camino para examinar cómo funciona la PDT en diferentes tipos de células, ya sean células cancerosas, bacterias, hongos o virus con una plataforma fácil, económica y versátil.

rose-bengal-mediated-photodynamic-therapy-to-inhibit-candida-albicans

Research

JoVE Journal

Immunology and Infection

Rose Bengal-Mediated Photodynamic Therapy to Inhibit Candida albicans

A 96 Well Microtiter Plate-based Method for Monitoring Formation and Antifungal Susceptibility Testing of Candida albicans Biofilms

Candida albicans remains the most frequent cause of fungal infections in an expanding population of compromised patients and candidiasis is now the third most common infection in US hospitals. Different manifestations of candidiasis are associated with biofilm formation, both on host tissues and/or medical devices (i.e. catheters). Biofilm formation carries negative clinical implications, as cells within the biofilms are protected from host immune responses and from the action of antifungals. We have developed a simple, fast and robust in vitro model for the formation of C. albicans biofilms using 96 well microtiter-plates, which can also be used for biofilm antifungal susceptibility testing. The readout of this assay is colorimetric, based on the reduction of XTT (a tetrazolium salt) by metabolically active fungal biofilm cells. A typical experiment takes approximately 24 h for biofilm formation, with an additional 24 h for antifungal susceptibility testing. Because of its simplicity and the use of commonly available laboratory materials and equipment, this technique democratizes biofilm research and represents an important step towards the standardization of antifungal susceptibility testing of fungal biofilms.

A 96 Well Microtiter Plate-based Method for Monitoring Formation and Antifungal Susceptibility Testing of Candida albicans Biofilms

We describe a simple, rapid and robust method for the formation of Candida albicans biofilms using 96 well microtiter plates and its utility in antifungal susceptibility testing of cells within biofilms.

A 96 de microtitulación y placa basada en el método para la formación de Control y pruebas de sensibilidad antifúngica Candida albicans Las biopelículas

Candida albicans remains the most frequent cause of fungal infections in an expanding population of compromised patients and candidiasis is now the third ...

Investigación

Inmunología e Infección

Visualization of Biofilm Formation in Candida albicans Using an Automated Microfluidic Device

Candida albicans is the most common fungal pathogen of humans, causing about 15% of hospital-acquired sepsis cases. A major virulence attribute of C. albicans is its ability to form biofilms, structured communities of cells attached to biotic and abiotic surfaces. C. albicans biofilms can form on host tissues, such as mucosal layers, and on medical devices, such as catheters, pacemakers, dentures, and joint prostheses. Biofilms pose significant clinical challenges because they are highly resistant to physical and chemical perturbations, and can act as reservoirs to seed disseminated infections. Various in vitro assays have been utilized to study C. albicans biofilm formation, such as microtiter plate assays, dry weight measurements, cell viability assays, and confocal scanning laser microscopy. All of these assays are single end-point assays, where biofilm formation is assessed at a specific time point. Here, we describe a protocol to study biofilm formation in real-time using an automated microfluidic device under laminar flow conditions. This method allows for the observation of biofilm formation as the biofilm develops over time, using customizable conditions that mimic those of the host, such as those encountered in vascular catheters. This protocol can be used to assess the biofilm defects of genetic mutants as well as the inhibitory effects of antimicrobial agents on biofilm development in real-time.

Visualization of Biofilm Formation in Candida albicans Using an Automated Microfluidic Device

This protocol describes the use of a customizable automated microfluidic device to visualize biofilm formation in Candida albicans under host physiological conditions.

Visualización de la formación de Biofilm de Candida albicans utilizando un dispositivo microfluídico automatizado

Candida albicans is the most common fungal pathogen of humans, causing about 15% of hospital-acquired sepsis cases. A major virulence attribute of C. ...

Deep Dermal Injection As a Model of Candida albicans Skin Infection for Histological Analyses

The skin is an extremely extended organ of the body and, due to this large surface, it is continuously exposed to microorganisms. Skin damage can easily lead to infections in the dermis which can, in turn, result in the dissemination of pathogens into the bloodstream. Understanding how the immune system fights infections at the very early stage and how the host can eliminate the pathogens is an important step to set the base for future therapeutic interventions. Here we describe a model of Candida albicans infection that can visualize the processes that occur early during an infection, including when the pathogen has passed the epithelial barrier, as well as the immune response elicited by the C. albicans invasion. We used this infection model to perform histological analyses that show the immune cells that infiltrate the skin as well as the presence and localization of the pathogen. Samples collected after the infection can be processed for RNA extraction.

Deep Dermal Injection As a Model of Candida albicans Skin Infection for Histological Analyses

Here we describe a protocol that allows histological and molecular analysis of skin samples after Candida albicans intradermal injection. This protocol maintains the structural integrity of the skin and allows for the localization of tissue-resident or newly recruited immune cells as well as the pathogen distribution.

Profundo dérmico inyección como un modelo de infección de la piel Candida albicans para el análisis histológico

The skin is an extremely extended organ of the body and, due to this large surface, it is continuously exposed to microorganisms. Skin damage can easily ...

Daily Phototherapy with Red Light to Regulate Candida albicans Biofilm Growth

Here, we present a protocol to assess the outcomes of per diem red light treatment on the growth of Candida albicans biofilm. To increase the planktonic growth of C. albicans SN425, the inoculums grew on Yeast Nitrogen Base media. For biofilm formation, RPMI 1640 media, which have high concentrations of amino acids, were applied to help biofilm growth. Biofilms of 48 h were treated twice a day for a period of 1 min with a non-coherent light device (red light; wavelength = 635 nm; energy density = 87.6 J&#183;cm-2). As a positive control (PC), 0.12% chlorhexidine (CHX) was applied, and as a negative control (NC), 0.89% NaCl was applied to the biofilms. Colony forming units (CFU), dry-weight, soluble and insoluble exopolysaccharides were quantified after treatments. Briefly, the protocol presented here is simple, reproducible and provides answers regarding viability, dry-weight and extracellular polysaccharide amounts after red light treatment.

Daily Phototherapy with Red Light to Regulate Candida albicans Biofilm Growth

Here, we present a protocol to assess the outcome of red light application on the growth of Candida albicans biofilm. A non-coherent red light device with the wavelength of 635 nm and energy density of 87.6 J&#183;cm-2 was applied throughout the growth of Candida albicans biofilms for 48 h.

Diario fototerapia con luz roja para regular crecimiento de Biofilm de Candida albicans

Here, we present a protocol to assess the outcomes of per diem red light treatment on the growth of Candida albicans biofilm. To increase the planktonic ...

Visualization of Candida albicans in the Murine Gastrointestinal Tract Using Fluorescent In Situ Hybridization

Candida albicans is a fungal component of the gut microbiota in humans and many other mammals. Although C. albicans does not cause symptoms in most colonized hosts, the commensal reservoir does serve as a repository for infectious disease, and the presence of high fungal titers in the gut is associated with inflammatory bowel disease. Here, we describe a method to visualize C. albicans cell morphology and localization in a mouse model of stable gastrointestinal colonization. Colonization is established using a single dose of C. albicans in animals that have been treated with oral antibiotics. Segments of gut tissue are fixed in a manner that preserves the architecture of luminal contents (microorganisms and mucus) as well as the host mucosa. Finally, fluorescent in situ hybridization is performed using probes against fungal rRNA to stain for C. albicans and hyphae. A key advantage of this protocol is that it allows for simultaneous observation of C. albicans cell morphology and its spatial association with host structures during gastrointestinal colonization.

Visualization of Candida albicans in the Murine Gastrointestinal Tract Using Fluorescent In Situ Hybridization

The purpose of this protocol is to visualize Candida albicans cell shape and localization in the mammalian gastrointestinal tract.

Visualización de Candida albicans en el tracto gastrointestinal murino utilizando hibridación fluorescente in situ

Candida albicans is a fungal component of the gut microbiota in humans and many other mammals. Although C. albicans does not cause symptoms in most ...

Clarifying and Imaging Candida albicans Biofilms

The microbial fungus Candida albicans can undergo a change from commensal colonization to virulence that is strongly correlated with its ability to switch from yeast-form growth to hyphal growth. Cells initiating this process become adherent to surfaces as well as to each other, with the resulting development of a biofilm colony. This commonly occurs not only on mucosal tissue surfaces in yeast infections, but also on medical implants such as catheters. It is well known that biofilm cells are resistant to antifungal drugs, and that cells that shed from the biofilm can lead to dangerous systemic infections. Biofilms range from heavily translucent to opaque due to refractive heterogeneity. Therefore, fungal biofilms are difficult to study by optical microscopy. To visualize internal structural, cellular, and subcellular features, we clarify fixed intact biofilms by stepwise solvent exchange to a point of optimal refractive index matching. For C. albicans biofilms, sufficient clarification is attained with methyl salicylate (n = 1.537) to enable confocal microscopy from apex to base in 600 &#181;m biofilms with little attenuation. In this visualization protocol we outline phase contrast refractometry, the growth of laboratory biofilms, fixation, staining, solvent exchange, the setup for confocal fluorescence microscopy, and representative results.

Clarifying and Imaging Candida albicans Biofilms

To view and quantify the internal features of Candida albicans biofilms, we prepare fixed intact specimens that are clarified by refractive index matching. Then, optical sectioning microscopy can be used to obtain three-dimensional image data though the full thickness of the biofilm.

Aclaración e imagen de Candida albicans Biofilms

The microbial fungus Candida albicans can undergo a change from commensal colonization to virulence that is strongly correlated with its ability to switch ...

An Ex vivo Assay to Study Candida albicans Hyphal Morphogenesis in the Gastrointestinal Tract

Candida albicans hyphal morphogenesis in the gastrointestinal (GI) tract is tightly controlled by various environmental signals, and plays an important role in the dissemination and pathogenesis of this opportunistic fungal pathogen. However, methods to visualize fungal hyphae in the GI tract in vivo are challenging which limits the understanding of environmental signals in controlling this morphogenesis process. The protocol described here demonstrates a novel ex vivo method for visualization of hyphal morphogenesis in gut homogenate extracts. Using an ex vivo assay, this study demonstrates that cecal contents from antibiotic treated mice, but not from untreated control mice, promote C. albicans hyphal morphogenesis in the gut content. Further, adding back specific groups of gut metabolites to the cecal contents from antibiotic-treated mice differentially regulates hyphal morphogenesis ex vivo. Taken together, this protocol represents a novel method to identify and investigate the environmental signals that control C. albicans hyphal morphogenesis in the GI tract.

An Ex vivo Assay to Study Candida albicans Hyphal Morphogenesis in the Gastrointestinal Tract

The ex vivo assay described in this study using gut homogenate extracts and immunofluorescence staining represents a novel method to examine the hyphal morphogenesis of Candida albicans in the GI tract. This method can be utilized to investigate the environmental signals regulating morphogenetic transition in the gut.

Un ensayo ex vivo para estudiar Candida albicans Morphogenesis hifal en el tracto gastrointestinal

Candida albicans hyphal morphogenesis in the gastrointestinal (GI) tract is tightly controlled by various environmental signals, and plays an important ...

Use of In Vivo Imaging to Screen for Morphogenesis Phenotypes in Candida albicans Mutant Strains During Active Infection in a Mammalian Host

Candida albicans is an important human pathogen. Its ability to switch between morphologic forms is central to&#160;its pathogenesis; these morphologic changes are regulated by a complex signaling network controlled in response to environmental stimuli. These regulatory components have been highly studied, but almost all studies use a variety of in vitro stimuli to trigger filamentation. To determine how morphogenesis is regulated during the pathogenesis process, we developed an in vivo microscopy system to obtain high spatial resolution images of organisms undergoing hyphal formation within the mammalian host. The protocol presented here describes the use of this system to screen small collections of C. albicans mutant strains, allowing us to identify key regulators of morphogenesis as it occurs at the site of infection. Representative results are presented, demonstrating that some regulators of morphogenesis, such as the transcriptional regulator Efg1, have consistent phenotypes in vitro and in vivo, whereas other regulators, such as adenyl cyclase (Cyr1), have significantly different phenotypes in vivo compared to in vitro.

Use of In Vivo Imaging to Screen for Morphogenesis Phenotypes in Candida albicans Mutant Strains During Active Infection in a Mammalian Host

This manuscript describes a method for screening moderately sized Candida albicans mutant libraries for morphogenesis phenotypes during active infection in a mammalian host using non-invasive confocal microscopy.

Uso de imágenes in vivo para detectar fenotipos de morfogénesis en cepas mutantes de Candida albicans durante la infección activa en un huésped mamífero

Candida albicans is an important human pathogen. Its ability to switch between morphologic forms is central to&#160;its pathogenesis; these morphologic ...

APDT eficaz con curcuminoides para la candidiasis oral en ratones

Curcuminoid-Mediated Antimicrobial Photodynamic Therapy on a Murine Model of Oral Candidiasis

Antimicrobial Photodynamic Therapy (aPDT) has been extensively investigated in vitro, and preclinical animal models of infections are suitable for evaluating alternative treatments prior to clinical trials. This study describes the efficacy of aPDT in a murine model of oral candidiasis. Forty mice were immunosuppressed with subcutaneous injections of prednisolone, and their tongues were inoculated using an oral swab previously soaked in a C. albicans cell suspension. Tetracycline was administered via drinking water during the course of the experiment. Five days after fungal inoculation, mice were randomly distributed into eight groups; a ninth group of untreated uninfected mice was included as a negative control (n = 5). Three concentrations (20 &#181;M, 40 &#181;M, and 80 &#181;M) of a mixture of curcuminoids were tested with a blue LED light (89.2 mW/cm2; ~455 nm) and without light (C+L+ and C+L- groups, respectively). Light alone (C-L+), no treatment (C-L-), and animals without infection were evaluated as controls. Data were analyzed using Welch&#39;s ANOVA and Games-Howell tests (&#945; = 0.05). Oral candidiasis was established in all infected animals and visualized macroscopically through the presence of characteristic white patches or pseudomembranes on the dorsum of the tongues. Histopathological sections confirmed a large presence of yeast and filaments limited to the keratinized layer of the epithelium in the C-L- group, and the presence of fungal cells was visually decreased in the images obtained from mice subjected to aPDT with either 40 &#181;M or 80 &#181;M curcuminoids. aPDT mediated by 80 &#181;M curcuminoids promoted a 2.47 log10 reduction in colony counts in comparison to those in the C-L- group (p = 0.008). All other groups showed no statistically significant reduction in the number of colonies, including photosensitizer (C+L-) or light alone (C-L+) groups. Curcuminoid-mediated aPDT reduced the fungal load from the tongues of mice.

Autor destacado: Explorando la terapia fotodinámica con curcumina en un modelo murino para la candidiasis oral

This protocol describes the application of antimicrobial Photodynamic Therapy (aPDT) in a murine model of oral candidiasis. aPDT was performed using a water-soluble mixture of curcuminoids and blue LED light.